Saturday family
Zak Saturday
Zak Saturday is the 11-year-old (he turns 12 in "Kur" and turns 13 in "Life in the Underground") major character of the show. The son of Doc and Drew Saturday, Zak seeks adventure at every turn, which is easily satisfied by his cryptid-researching family. Zak has an unorthodox upbringing that has taken him around the planet and placed him in the face of danger since the day he was born. Zak was born the same year the Kur Stone was found and has a special psychic ability to connect with cryptids, allowing him to control their actions to an extent. Tamer cryptids seem to trust him instinctively and even fiercer ones can tell that Zak is different from other humans.
Zak's primary weapon is the Claw, a combination staff/grappling hook which acts as a focusing device for his powers. Zak also seems stronger and more durable than a normal child his age.
For a while, it was believed that if the cryptid Kur was ever unleashed, Zak would be the only one with the power to stop it. However, it was eventually learned that the Kur Stone Doc and Drew discovered before Zak's birth contained Kur's essence. When it was uncovered, the energy was released from the stone and found a new host in Zak. [2] Despite the Saturdays trying to keep this a secret, the other Secret Scientists found out through unexplained means and began pursuing Zak, forcing the Saturdays to go on the run. The Nagas have also sought him, intending to have him embrace his inner nature and become their new master. Following Rani Nagi's attack on Manhattan, Argost approaches Zak and Fiskerton, offering to help the former master his abilities. Zak agrees to the plan, though Argost has informed him that he has his own hidden agenda. In the series finale, Zak apparently loses his powers after Argost drains them with the Flute of Gilgamesh. However, the Ben 10: Omniverse crossover "T.G.I.S." reveals that he retains them, albeit in a weakened and residual state.
Solomon "Doc" Saturday
Solomon "Doc" Saturday is the patriarch and the "Indiana Jones"-like character who has spent his whole life studying cryptids. Doc Saturday naturally had black hair but after a fight with a guardian known as Tsul 'Kalu, Doc was shocked by the claw that originally belonged to Kalu, giving him a streak of white hair and blinding him in his right eye. A man who takes science very seriously, Doc is one of the Earth's leading experts in the field of cryptozoology.
Doc started his career on Honey island when he was 12, learning from Dr. Basil Lancaster. He is a supergenius, having built many of the gadgets the family uses. A loving father, he often tries to teach his son Zak responsibility. Doc is trained in fourteen different forms of martial arts. He fights with the Battle Glove, which can channel power into his right fist. The four crystals on the knuckles also have individual powers: freezing, heating, shocking, and sonic vibrations. Though his age is not definite, creator Jay Stephens has stated that he "imagined Doc as 40 or so."
Drew Saturday
Drew Saturday is the matriarch and the one who "believes in magic," being more prone to accepting things on faith rather than empirical evidence. Drew was born to a family of adventurer-scientists. After her family was scattered during a severe blizzard in the Himalaya, she was raised by monks who may have taught her to believe not everything needs a reasonable/scientific explanation. Years later, she was reunited with her long lost brother, Doyle. She is able to speak 37 different languages which, in many episodes, comes in handy. Drew is always encouraging Zak to try new things like tribal dancing or sand painting, but when there's a risk of danger, Drew gets a little overly protective of her only son. She's a mystic who is well-versed in the Earth's cultures and can blend in anywhere her travels may take her. In "And Your Enemies Closer", she and Doyle reunited in the Himalayas at the same place that their family was lost. She then learns that it wasn't the blizzard that separated her and Doyle, but an attack on their camp by Argost.
Drew's preferred weapon is the Tibetan Fire Sword that was given to her by the monks, which absorbs light and channels it into potent bursts of flame. Her sword needs light to access the fire; if there is no light source around, it shoots blue flames. In "Food of the Giants" she shows her skill as an expert at wilderness survival. Like Doc, she is a skilled fighter. Though her age is not definite, Jay Stephens stated that he "imagined her as 34 or so."
Fiskerton
Fiskerton is a seven-foot-tall "gorilla-cat" with glowing red eyes, based on the Fiskerton Phantom. He was adopted by the Saturday family after his home in Nottinghamshire was destroyed. Although he is the oldest and largest member of the family, Fiskerton is like an innocent brother to Zak. He may be a coward at times, but he is proven to be a great and strong ally to have, willing to risk his life for his new family. He mostly talks in grunts and mumbling which occasionally mimic human speech, though the family is able to understand him regardless. Even though Fiskerton is a cryptid and not human, he and Zak share a brotherly friendship.
Fiskerton has great strength, as he is capable of ripping apart metal bare-handed and hold his own against larger cryptids. His feet are as dexterous as his hands, allowing him to climb things with ease. In "Once More the Nightmare Factory", it is revealed that Fiskerton is a Lemurian, a member of a race of creatures that guard the Earth against Kur and can locate it through psychic and instinctual means.
Komodo
Komodo is a 250-pound, genetically-altered Komodo dragon with a voracious appetite. He can become invisible and make other objects invisible, which comes in handy for stealth missions. Though for the most part he is very obedient, Komodo's actions are often dictated by his stomach and he will ignore the family for a good meal. Extending from this, Komodo will often pick fights with others to get food, even when his opponent is far larger and stronger. Like Fiskerton, Zak sees him as a brother.
Zon
Zon, named after the Amazon rainforest where she was found, is an Ornithocheirus who lives in a nest near the Saturday Headquarters, but is not truly owned by them. The Saturdays anger her by crashing into her nest during the second episode, but she comes to appreciate them after Zak saves her life. She now uses the cliffs where the Saturdays live as her new hunting grounds. Unafraid of humans, she allows Zak to comb her mane and ride her, but resists the family's domestication efforts and refuses to give up the great outdoors. Like Komodo and Fiskerton, Zak sees her as a family member, in this case as a sister. In "Kur, Part 1," Zon is revealed to be aiding Doyle in locating the missing V.V. Argost. She is currently helping Doyle find information about Argost's past.
Doyle Blackwell
Doyle is Zak's biological uncle, Doc's brother-in-law and Drew's long-lost younger brother. He first appears as Van Rook's apprentice in "The Kur Stone". He helps Zak put a tribe of Amaroks back into hibernation in "The Ice Caverns of Ellef Ringnes", starting a stable relationship with him. At first, he and the Saturdays are unaware of any biological relationship between them. In "Van Rook's Apprentice", he changes sides and joins the Saturdays after learning he is Drew's brother and about V.V. Argost's true motives.
Though Doyle is admired by Zak, he and Drew have a small sibling rivalry and at first, he and Doc barely get along at all. Doc is annoyed by Doyle's tendency to show off and is also frustrated by Doyle's chaotic lifestyle, which proves an unfortunate influence on Zak. Doyle resents what seems to him to be constant criticism by Doc of his methods and tactics, as well as what he perceives to be Doc being judgmental of his mercenary trade. Eventually, they make up, as the threat from Argost grows greater and Doc recognizes the potential value of Doyle's unique skills. Doyle is something of a jack-of-all-trades, fighting using a combination of grenades, lasers, as well as hand-to-hand combat. He is strong enough to lift a grown man one-handed and wrestle with cryptids much larger than himself.
As shown in "The Atlas Pin" he's shown to be not entirely reformed as he was willing to go behind Drew's back to gather the pieces of Rani Nagi's Kur relic. It was mostly because of Doyle that Kur was revealed to be Zak as he repaired the relic and brought it into the proximity of Zak at the end of "Kur Rising". Jay Stephens himself has already said that he imagined Doyle to be "28 or so".
In "Kur", Doyle, aided by Zon and Van Rook, is looking for the missing V.V. Argost. After finding what seemed to be proof that Argost was dead, he reported his findings to the family. Zak secretly informed him that Argost was indeed still alive and asked him to search for information regarding Argost's past. With Zon and Van Rook continuing to aid him, he tracked down those who had connections to Argost's past, but it proved difficult as they kept not-so-mysteriously disappearing. In "And Your Enemies Closer", his search led him to the Himalayan monks who had raised Drew after they were separated. Upon reuniting with Drew, she informs him that it was here that they lost their parents. Doyle recalls that he ended up sliding down the slope and wound up in an orphanage, which led to the way he grew up. He then reveals something shocking to Drew: it was not the storm that ruined their family, but an attack from a cryptid called a Yeti. Upon finding the beast's abandoned lair, Doyle and Drew learn that it was Argost who attacked their family and separated them.
Allies and neutral characters
Leonidas Van Rook
Leonidas Van Rook is a ruthless cryptozoologist who is the ally of V.V. Argost and a rival of Doc Saturday. Van Rook is interested in proving the existence of cryptids for money. He is very thrifty, almost to a fault. Similar to Doc, he is an inventor and has many high-tech gadgets. He and Drew dated in college, much to her dismay. After Doyle left him, Van Rook hired Abbey Grey. In "Kur", Van Rook admits that he trained Abbey too well because she has taken over the mercenary business from him. He seems to have gotten out of shape between Season 1 and Season 2: Doyle pointed out that he had some extra gut room in his armor and he even admitted he was out of shape while fighting Munya. He has been recruited by Doyle to find V.V. Argost after he found Van Rook working with Ron Bantington. When Doyle and his quest to learn the secrets of Argost's past leads to the Himalayas, they are reunited with Drew, who does not greet Van Rook with open arms, it is also shown that even he is disgusted that Argost only attacked people for sadistic pleasure.
He fought alongside the Saturdays in "War of the Cryptids", against Argost's cryptid army. He ultimately sacrifices himself to save Drew Saturday from Rani Nagi. After Argost is killed and his cryptid army retreated, the Saturdays and their friends paid their respects to him.
Secret Scientists
The Secret Scientists are a group of Earth's greatest minds that specialize in various fields:
Dr. Arthur Beeman
Dr. Arthur Beeman is a Secret Scientist who studies aliens and UFOs. However, far from being a conspiracy nut, his obsession is apparently justified as he saved the Earth from invasion by figuring out the 'crop circle code'. Beeman is often blunt and mildly insulting in his speech. Doc and Drew called him in to watch Zak, Fiskerton, Komodo, and Zon while they were away on their anniversary dinner. In "War of the Cryptids", it is revealed that he has a recording from the Flute of Gilgamesh, with which he unsuccessfully tries to kill Zak and Argost.
Dr. Henry Cheveyo
Dr. Henry Cheveyo is another Secret Scientist who held a piece of the Kur Stone. Argost stole it, then used a cryptid parasite to extract the location of the third piece from him. He works at the Mesa Observatory in Arizona. He was seriously wounded when he took the brunt of an explosion meant to kill the Saturdays, but survived.
Dr. Miranda Grey
Dr. Miranda Grey is a Secret Scientist who held a piece of the Kur Stone until Munya stole it. She specializes in quantum physics and wields a gun which can create miniature wormholes, allowing her to physically attack opponents from a distance. She is Abbey Grey's sister and was dissatisfied that she sided with Leonidas Van Rook. In "Kur" Pt. 1, she is one of the scientists after Zak. In "The Thousand Eyes of Ahuizoti," it's revealed that she has been watching Weird World for surveillance. In "War of the Cryptids," Miranda has a change of heart and saves Zak from the Flute of Gilgamesh.
Deadbolt
Deadbolt is Miranda Grey's robotic sidekick. It is a recurring joke that in every episode he appears in, he is destroyed only to come back later new and improved.
Dr. Paul Cheechoo
Dr. Paul Cheechoo is a Secret Scientist from Canada who specializes in cold-climate research. He and a team of experts travel the Earth studying strange geological anomalies. He's currently stationed at Ellef Ringnes in the Arctic Circle. The Saturdays tend to cause, or at least get involved in, ecological disasters when they do any work near him, which he eventually points out with slight annoyance. He also has more of a sense of humor than the other Secret Scientists and seem to be the most friendly with Zak. He attended Van Rook's funeral.
Professor Talu Mizuki
Professor Talu Mizuki is a scientist who invented a mind-swapping device for crime lord and philanthropist Shoji Fuzen where Mizuki wanted to use the device to give certain people a new body. When asked to use it to implant the mind of one of Fuzen's men into a Hibagon, he takes the Hibagon's body himself to prevent Fuzen from obtaining and weaponizing it. In the ensuing confrontation, his body is lost in a fire and the mind-swapping device is destroyed. He attempts to take revenge against Fuzen, but is convinced by Doc to let it go. He now lives in a cave lab alongside his white tiger working on rebuilding the device, and joined the Secret Scientists.
White Tiger
This white tiger is the result of Talu Mizuki's mind-swapping project where he swapped it with the mind of his dog. After the accident that caused Talu's mind to be in a Hibagon, the white tiger still remains with Mizuki.
Dr. Pachacutec
A member of the Secret Scientists who is seen in "Eterno". She and the other scientists were at the meeting and discovered that the rivers have turned to salt in the Middle East. She and the other scientists helped Zak, Wadi, and Fiskerton to get the sap from the Methuselah Tree. Once they return to the surface, Zak accidentally drops the bottle containing the sap, which splashes onto Drew and destroys some of the salt on her. Eventually, the scientists are able to replicate the sap and use it to free everyone who was trapped in salt.
Dr. David Bara
A member of the Secret Scientists who is seen in "Shadows of Lemuria" and "And Your Enemies Closer".
In his first appearance, he uses his Dream-Time Totem to put Fiskerton to sleep and find the motivation behind his instinctual behavior. Argost sends a neural parasite to control Fiskerton, who builds an army of robotic duplicates of himself to attack the Saturdays' headquarters. After Zak defeats the parasite, Fiskerton uses the remains of the headquarters to build a divining rod and locate Kur.
In his second appearance, Bara is among the scientists trying to capture a Revolving Beast.
Dr. Odele
A member of the Secret Scientists specializing in anomalous weather.
In "The Kur Stone", he told Doc that Henry Cheveyo was greatly injured by Argost's firecracker beetles, but would recover. He also believes that Argost is heading to Manaus, Brazil. He also suggested the Saturdays to leave Zak with him, while the rest of them get the last piece of the Kur Stone. This made Zak upset, but Doc suggested that Zak will stay with his family.
In "The King of Kumari Kandam", Odele called the Saturdays to inform them that the citizens of Kumari Kandam attacked him and his people somewhere in the Indian Ocean.
In "Eterno", he was seen at the meeting with the other scientists.
Ulraj
The young fish-like prince of Kumari Kandam, whose father was killed in an assault orchestrated by V.V. Argost. He allied with Zak to reclaim his kingdom from Argost. With help from the Saturdays, Ulraj reclaimed his kingdom, but V.V. Argost and Munya escaped with an ancient and powerful Sumerian medallion. Afterwards, Ulraj becomes an ally and friendly rival to the Saturdays.
Agent Epsilon
Agent Epsilon and his 11-year-old "son" Francis are members of a secret organization loosely allied with the Secret Scientists, though they have their own agenda. Epsilon is usually quite serious and by the book, personifying the "Men in Black" archetype. He also has access to "the files", a massive database of information. "The Unblinking Eye" reveals that he and Francis are clones of a "perfect agent" their organization found a century prior.
Francis
The 11-year-old "son" of Agent Epsilon. Francis is clever and manipulative, just like his "father", and wields a device that can generate electric shields. Additionally, he is rivals with Zak, in part because of his jealousy towards him having a "normal" family. After Francis discovers his nature as a clone, Zak consoles him and convinces him to take charge of his fate, after which he allows him to escape.
Maboul
Maboul is the father of Wadi and the chieftain of the Hassi who guard the Methuselah Tree (the source of all water on Earth). He disapproves of Wadi's kleptomaniac ways. In "Curse of the Stolen Tiger," he has the Saturdays babysit Wadi while he is away on Hassi business. He is good friends with Drew Saturday. He and Wadi, as well as some members of the Hassi took part in the fight against Argost's cryptid army.
Wadi
Wadi is the daughter of Maboul and Zak's love interest. Wadi is a kleptomaniac, which her father disapproves of. In "Eterno", she steals a salt crystal which inadvertently awakens the salt creature Eterno. She aids Zak in stopping it, building a love-hate friendship. She later assists the Saturdays in reclaiming a village's stolen blue tiger from Shoji Fuzen, with Wadi helping to defeat him by stealing a component from his armor. In the episode "Life in the Underground", Wadi shows that she has a crush on Zak and reveals that she copied his idea of "the claw" with a yo-yo.
Wadi participated alongside her tribe in "War of the Cryptids" alongside the rest of the Hassi.
A skilled cryptid warrior, known for his devotion to catch his targets no matter what. Years ago he challenged Doc to a fight due to an accident caused by Zak which destroyed an archeological place guarded by him. In the ensuing fight, Doc won but at the cost of a blinded eye and a scar on his face. As a token of honor, Tsul 'Kalu gave him his amulet, a claw, which was to be used later on Zak's weapon. In the present he tracked Zak down, having learned that he is Kur and tried to reclaim the amulet, not wanting it to be used for evil purposes. After losing the battle against Zak, he was able to see his true intentions and permitted Zak to use the power of the Claw, becoming an ally to the Saturdays.
Tiacapan
Tiacapan is a young Mexican girl (around 11-12) who appears in "The Thousand Eyes of Ahuizotl". She helps the Saturdays battle the titular cryptid, Ahuizotl (voiced by Fred Tatasciore). [6]
Swamp Cryptids
A group of artificial cryptids created by Basil Lancester, whom they remain loyal to even after his death. They initially attack the Saturdays, but ultimately help them after revealing that they were working to destroy the project that created them.
Momo
Momo is a Bigfoot-like creature with hair covering most of its face.
Honey Island Swamp Monster
In this show, the Honey Island Swamp Monster is a Bigfoot-like creature with a monkey-like head, crocodilian feet, and crab-like claws.
Lake Worth Monster
The Lake Worth Monster is a hairy creature that has the head and hooves of a goat. It was the one who showed Doc and Drew the message from Dr. Lancaster and helped to intimidate Dr. Lee and his colleagues into undoing the fusion done to Zak, Fiskerton, and Komodo.
Kinchafoonee Creep
The Kinchafoonee Creep is a bat-headed creature with wild boar-like tusks.
Georgia Pigman
The Georgia Pigman is a pig-headed ape-like creature.
Bardin Booger
The Bardin Booger is a Bigfoot-like creature.
Devil Monkey
The Devil Monkey is a monkey-like creature with horns.
Green Goon
The Green Goon is an ape-like creature.
Hawley Him
The Hawley Him is a black-furred Bigfoot-like creature.
Mississippi Swamp Ape
The Mississippi Swamp Ape is a "bearded" Bigfoot-like creature.
Fouke Monster
The Fouke Monster is a Bigfoot-like Cryptid.
In "War of the Cryptids", the Fouke Monster was among the cryptids who fought Munya during his invasion of Paris.
Tibetan Monks
A group of monks from the Himalayas. They were mentioned in "Van Rook's Apprentice" and make an actual appearance in "And Your Enemies Closer".
Drew mentioned that after she was separated from her family, the Tibetan monks found her and raised her in their temple. After she got older, the monks gave her a Tibetan Fire Sword.
In "And Your Enemies Closer", Doyle, Zon, and Van Rook visit the Himalayas and they find Drew. The monks arrived and welcomed Drew for returning to the Himalayas. In the temple, the monks were giving them tea. Van Rook was disgusted by the tea and asked how to say "taste like yak vomit" in Tibetan, causing one of the monks to hit him on the head. Doyle was telling Drew that Argost and Munya have captured Baron Finster, but wasn't sure why he abducted the Xing-Xing, but he knew it was also from the Himalayas.
When they went outside, Doyle knew the area where they lost their parents. Drew thought it was the storm, but it was actually a mysterious cryptid that killed them and push Doyle to the village. Doyle thought the Xing-Xing was the creature that attacked his parents. Drew then told Doyle that they never knew that there was a cryptid in the Himalayas. The monks then looked at each other and Drew got upset at them that they knew and never told her. They said that the cryptid is called the Yeti and her parents were not its only victims in those days. They said that they tried to hunt it down countless times, but when they finally found its lair, the beast was gone. They then showed Drew and the others to the Yeti's lair. Doyle was still upset about the "orange Yeti freak" for letting it go. However, one of the monks said that the Yeti doesn't have orange fur, but is pure white with pale blue skin and they suggested it was not the cryptid he saw.
Bud Harger
A logger operating in the Allegheny Mountains, who appears in "Food of the Giants". He and his three workers decided to make a city by cutting down trees, but one night, a large cryptid called the Allegewi (voiced by Fred Tatasciore) [6] attacked their campsite and abducted two of his workers. Subsequently, he enlists the Saturdays to rescue them and defeat the monster.
Ruby, Cody, and Wyatt
Three loggers who work for Bud Harger. Two of the workers (Cody and Wyatt) were captured by an Allegewi. When Wyatt escaped from the beast's lair, he led the Saturdays in an attempt to rescue Cody. When they reached the Allegewi's lair, the cryptid tries to catch Cody, who is hiding in a crevice. They managed to rescue him and defeat the Allegewi (thanks to Abbey, who lured it to a chasm).
Dr. Basil Lancaster
A scientist, who was a friend of Doc Saturday when he was young. He was seen in "Ghost in the Machine". He and Doc worked with Dr. Lee and three unnamed scientists with a machine to create cryptids on Honey Island Swamp by mutating humans. However, he came to regret his actions and entrusted his creations with destroying the project before leaving the area.
Honoring Lancaster's final request, the Saturdays and the cryptids destroy all that remained of the project. Dr. Lee and the other three scientists are sent to prison by the US Army. Doc also takes the photo that shows a younger version of him and Lancaster. The message ends that Lancaster knows that Doc is a better man.
Villains
V.V. Argost
V.V. Argost is the series' main villain and the archenemy of the Saturdays. He is the host of V.V. Argost's Weirdworld, a series that made him "the modern master of the bizarre" of the Earth. With an extensive knowledge of cryptids as well as a showy and dramatic personality, Argost's overall goal is the possession of Kur and the power it holds. Having hid his true nature well, Argost is actually a Yeti that had been attacking humans out of enjoyment in the Himalayas and often took items from their camp as souvenirs. According to Jay Stephens, one of the 'souvenirs' Argost had taken from a camp he had attacked was a television, from which he learned to speak English. Argost then resolves to live among humans by influencing them with a television show of his own. Donning a Megatooth shark skin cloak and mask, Argost lived on the streets before acquiring the funding he needed from Baron Finster in return for his scorpion lower body.
In "Kur Rising", Argost takes control of a creature he and the Saturdays believe to be Kur before the monster is defeated and he is taken to safety by Munya when Zak cracks his mask. Throughout the second season, while using Munya to give the Saturdays the notion that he had died, Argost went into hiding before saving Zak from Rani Nagi and offered to help him hone his Kur powers. However, as was revealed in "Legion of Garuda", Argost possesses the flute of Gilgamesh with the intent to extract Zak's power while obtaining an orange ape-like cryptid from his past during the episode "Return of Tsul 'Kalu".
During the episode "And Your Enemies Closer", as Dolye and Drew eventually learn of his true nature and his role in their parents' death in the Himalayas, Argost kidnaps Zak and takes him to an island where he revealed that during the events of "Into The Mouth of Darkness" when he hacked into the Saturdays' airship computer in a search for a means to extract Zak's Kur powers, he learned about the existence of the Saturdays' evil counterparts, the Mondays. The research had Argost realize that Zak Monday is logically the Anti-Kur, so he stole the Smoke Mirror of Tezcatlipoca from the Paris museum to bring the anti-matter Zak into their reality and siphon the Anti-Kur into himself. Once the ritual is completed, since he is now immune to Zak's powers, Argost destroys the relics to keep his new powers while revealing his true identity. Soon after, in the series finale "War of the Cryptids," Argost set his plans into motion, unleashing a gigantic cryptid army all over the Earth. However, his arrogance proves to be his undoing when he siphons Zak's powers in an attempt to amplify his own, having recreated and weaponized the Flute Of Gilgamesh. Unable to hear Zak's warning of the danger of combining matter and anti-matter energies, Argost is killed by the two Kurs' energies and presumed dead.
The Ben 10: Omniverse crossover episode "T.G.I.S." sees Argost revived by Dr. Animo to be revived as a chimeric amalgamation of alien and cryptid DNA. Ultimately he is defeated once again through the teamwork of Zak and Ben Tennyson, who drain his powers.
Munya
Munya is V.V. Argost's servant, injected with the DNA of a Papuan giant spider, enabling him to transform into a humanoid spider monster.
In "Kur" Pt. 2, Munya was using a special typewriter called a "text to speech engine" to help promote V.V. Argost's return. After learning that Doyle was searching for his secrets, Argost had Munya hunt down every person that was connected to his past on his orders, including Baron Finister.
In the episode "And Your Enemies Closer", it was shown that Munya had enough cryptid DNA to be controlled by Zak.
In "War of the Cryptids", Munya led an attack on Paris as part of Argost's army only to be defeated by Tsul 'Kalu, shortly after Argost's downfall.
Munya is once again at his master's side upon his revival by Dr Animo in the crossover episode "T.G.I.S" of Ben 10: Omniverse and also confronts Zak when he discovers Animo's lair, but is defeated in the ensuing fight.
Abbey Grey
Once Zak's babysitter, Abbey Grey is an ancient civilization expert and Miranda Grey's sister. She appears in "The Kur Guardian", helping Zak, Doyle, and Fiskerton in learning about Fiskerton's Lemurian roots. She and Doyle begin dating at the end of the episode, only for him to discover in "Food of the Giants" that Van Rook hired her not long after Doyle quit. She admits her feelings for Doyle were real, but still intends to finish the Saturdays off.
In "Kur Pt. 1", Van Rook mentioned to Doyle that Abbey Grey took over his business. Later it is revealed that she is much better in the field of mercenary work than Van Rook since not only does she make more money but can also buy higher grade equipment due to her not being as much of a cheap skate as her former teacher. Also it's shown that she, like her teacher, has come under the employment of Argost.
Rani Nagi
Rani Nagi is a four-armed Naga and the queen of her race. She can control any type of snake and speak through them. Her species is able to speak and breathe underwater.
When V.V. Argost captures Fiskerton, he calls her in to see if Fiskerton is Kur. She uses a relic forged from Kur's own essence which is said to glow in the presence of its master. When the artifact fails to glow, Argost asks her why the picture of Fiskerton was in Kur's tomb. She identifies him as a Lemurian, saying he can lead Argost to Kur. She then leaves before Doc charges in to face Argost. She later follows Zak, Doyle, Fiskerton, and Abby to Shangri-La to learn Kur's location. After a brutal battle in which she mostly holds her own against the family, she is finally defeated by Fiskerton.
She is seen later in "The Atlas Pin", where she is using her Kur-sensing relic around Kur's tomb, only for it to be stolen by Argost so he can use it to find Kur. She enlists the Saturdays' aid in retrieving her stolen relic by threatening to remove the Atlas Pin should they refuse to comply. Drew, Zak, and Komodo manage to stop her with help from Kumari Kandam, though she and her followers escape capture while Doc, Doyle, Fiskerton, and Zon recovered the artifact. However, when Drew learned that the Nagas were dark mystics, she says the relic must be destroyed which Fiskerton does. However, Doyle covertly recovers the pieces and repairs it.
Rani Nagi and her fellow Nagas returned in the season two premiere "Kur" as the main villains. After it was revealed that Zak is Kur, the Nagas sought him out while calling him their master. Rani attempted to convince Zak to tap into his inner nature and lead all cryptids in a war against humanity. Her attempt was interrupted by the timely arrival of the rest of the family and after a rough battle, they saved Zak and escaped. However, the Nagas had already succeeded in using Zak's power to summon cryptids from around the planet in a battle against humans. She and the other Nagas lead the army in the name of Kur. During the attack upon Manhattan, Rani Nagi was knocked away by V.V. Argost. Rani Nagi and her Nagas had possession of the Flute of Gilgamesh which Zak and Fiskerton stole. When Gokul attempts to kill Zak with the Flute, the Nagas help the Saturdays and the scientists that were after Zak stop him.
In "War of the Cryptids," Rani Nagi and her Nagas side with V.V. Argost after he claims the Anti-Kur powers from Zak Monday. She was responsible for using Drew's sword to attack her only for Leonidas to sacrifice his life by blocking the attack. She was later knocked out by the Saturdays after V.V. Argost's death.
Shoji Fuzen
Shoji Fuzen is a Japanese philanthropist who is also Japan's biggest crime lord. He tries to obtain a mind-swapping device invented by Talu Mizuki to transfer the mind of one of his followers into a Hibagon (a large, ape-like cryptid). Mizuki instead transfers his own mind into the creature, then goes on a rampage of revenge against Fuzen. The Saturdays convince Mizuki to abandon his revenge and send Fuzen to jail for his crimes.
He returns in the second season as a Chinese warlord after escaping from prison. He and his henchmen steal a luck-granting blue tiger from a small village. He is also now armed with samurai-themed armor, which he uses while engaging the Saturdays. During the battle, Fuzen is knocked off a cliff by Doc after Wadi steals a component from the suit which it needs for flight. It is unknown if he survived the fall.
Piecemeal
A criminally-insane chef with an appetite for rare animals. He has a surgically modified jaw made of four metal flaps which can bite through almost anything. He has above-average strength and durability, as he is able to knock out Fiskerton with a single punch and survive a direct blast from Drew's fire sword without injury. He attacks the Saturday household to kill Fiskerton, but is repelled by Zak using his mother's fire sword.
In "Target: Fiskerton", Argost hires him to help Leonidas Van Rook capture Fiskerton. Pietro instead tries to eat Fiskerton during the conflict on the train, so Argost uses a neuroparasite to knock him unconscious.
Baron Finster
Baron Finster is a cyborg with a mechanical scorpion tail and an enemy of Doyle. The Saturdays initially doubt his existence, but he turns out to be real.
In "Into the Mouth of Darkness", Doyle and Van Rook capture Finster to get information about Argost, but he is taken away by Munya. They did manage to find out that Argost designed Finster's body in exchange for funding for Weird World as well as the fact that Argost was once a poor man.
The Mondays
The Mondays are the Saturdays' evil antimatter duplicates from a parallel universe, summoned by the Smoke Mirror of Tezcatlipoca. They are not well liked in their reality, most likely being criminals. Each Monday has a distinguishing characteristic that sets them apart from the Saturdays, and cause reality to warp when in the presence of their duplicates. The name Monday was given to them by Zak Saturday since, according to him, his double is a "less fun version of a Saturday", hence a Monday.
The Mondays accidentally banish themselves back to their own universe while fighting over the mirror. The Saturdays leave and fail to notice that Zak and Komodo Monday escaping from the mirror while leaving the others behind, even when Drew Monday purposely threatened her son even though he's out of sight and can't hear her. In "Paris is Melting", the evil Zak and Komodo attempt to threaten Zak into retrieving their airship from the antimatter universe following their attack on Dr. Cheechoo, Dr. Lawhorn, and Dr. Grimes. Zak recovers it for them, but makes a deal with the rest of the Monday family while doing so. Zak drains the ship's power with their help before returning, causing it to crash back into the repaired Smoke Mirror. Zak Monday returned in "And Your Enemies Closer", where Argost tricked him so he could steal his power with the Flute of Gilgamesh. Afterwards, Argost destroyed both the flute and Smoke Mirror.
Zak Monday
His hair color reversed from Zak Saturday's along with his eyes glowing green when using his power with his Fang weapon, Zak Monday possesses the Anti-Kur power and uses it to drive cryptids insane rather than calming them. While Zak Saturday respects life, Zak Monday disregards it and has shown to be sadistic. Out of all the Monday family members, Zak Monday was the most reoccurring alongside Komodo Monday before they are sent back to their universe.
However in "And Your Enemies Closer" when summoned back to his counterpart's reality in what he later learned was a trap, Zak Monday is killed off when Argost uses the Flute of Gilgamesh to absorb the Anti-Kur spirit from him.
Doc Monday
Solomon "Doc" Monday's scarred eye is on the opposite side and he wears an eye patch over it. He usually speaks in incoherent babbling and has a much lower intellect than his counterpart. As shown in "Paris Is Melting", he has a power glove like Doc's, but it is gray and black, as well as fingerless and left-handed.
Drew Monday
Drew Monday has a long, prehensile tongue, but is otherwise similar to her counterpart. She is more rationally scientific than her counterpart. Whereas Drew Saturday comes off as rough but loves Zak, Drew Monday acts sweetly but hates Zak. Her sword shoots ice instead of fire like her counterpart.
Fiskerton Monday
Fiskerton Monday has horns in place of ears and is much more vicious than his counterpart.
Komodo Monday
Komodo Monday is capable of human speech and seems to be the leader of the group, when they're not fighting amongst themselves. He possesses black spots on his back which he can expand to cover his entire body and harden his skin.
Zon Monday
Zon Monday has eye-like patterns on her wings, but otherwise behaves almost exactly like Zon Saturday.
Kur
Kur is an ancient cryptid said to be a source of unlimited power and immortality for whoever can find and capture it, with the first season focusing on it due to its ability to control all other cryptids. The Saturdays and Argost are eventually led to Antarctica by Fiskerton, where they discover an ancient behemoth frozen in the ice. Believing this was the creature he sought, Argost took control of the cryptid from the inside and commanded its army of cryptid parasites, forcing Zak and Fiskerton to follow him into it. While inside, Zak's powers seemed to be stronger than ever and after a lengthy battle, he used his powers to bring down the behemoth that was believed to be Kur.
However, the actual Kur is revealed to be Zak as a result of the mystic energies infused in Zak while he was in the womb. With the added revelation that any attempt to remove the Kur spirit would kill him, Zak became targeted by various parties who would use his powers to their ends. One among them was Argost before he learned of Zak Monday and absorbed the Anti-Kur spirit, though Argost's greed got the better of them when he absorbed the Kur spirit from Zak. The interaction between the energies causes Argost to explode and seemingly be killed. However, as revealed in the Ben 10: Omniverse series, Argost was revealed to have actually been thrown into a state of anti-matter flux, with Kur's powers eventually returning to Zak once the flux ends.
Eterno
Eterno was once an ancient warrior king with an unquenchable thirst for conquest. His attempt to find the Methuselah Tree, the source of all water on Earth, led to him being entombed in salt by the tree's centipede-like protectors and eventually transformed into a humanoid salt monster with the ability to turn anything he touches into salt.
Upon awakening, Eterno turns the rivers of the Middle East into salt and traps all of the villagers in salt shells. He makes a deal for Zak to get sap from the tree and quench his thirst, in exchange for returning everything to normal. Eventually, Zak and Wadi retrieve a flower from the tree and bring it to Eterno, who drinks the sap from it and subsequently crumbles into inanimate salt.
Ron Barington
Ron Barington is the head of Bantington Industrial and a sponsor of Weird World. Doyle tracked him down to London, England to see if he knew anything about Argost.
Gokul
An Indian magician who can create illusions and summon images into the minds of his enemies. His group of people, long ago, performed a ritual that would defeat Kur. He offers to help the Saturdays destroy Kur by retrieving the Flute of Gilgamesh from the Nagas, but they turn against him after learning that this would also kill Zak.
Michel Grosshomme
An overweight man and illegal cryptid trader, appearing in "The Return of Tsul 'Kalu". Doyle, Van Rook, and Zon track him to Morocco to see if he knows anything about Argost's past.
Dr. Lee
A villainous scientist who is a colleague of Basil Lancaster and young Doc Saturday in a project to create cryptids in Honey Island Swamp. When the project went out of control, Dr. Lancaster betrayed him and the other three scientists by destroying enough of their research to cripple the project, saved the cryptids, and fled into the bayou. Years later, they lure the Saturdays to Honey Island Swamp and make Doc restart the project. However, after learning the truth, the Saturdays manage to defeat and arrest Lee and his accomplices.
