- Nachzehrer (German) – Anthropophagous undead
- Nāga (Buddhist and Hindu) – Nature and water spirits, serpentine or human-serpent hybrids
- Naga fireballs (Thai) – Spectral fire
- Nagual (Mesoamerica) – Human-animal shapeshifter
- Naiad (Greek) – Freshwater nymph
- Näkki (Finnish) – Water spirit
- Namahage (Japanese) – Ritual disciplinary demon from the Oga Peninsula
- Namazu (Japanese) – Giant catfish whose thrashing causing earthquakes
- Nando-baba (Japanese) – Old woman who hides under the floor in abandoned storerooms
- Nang Takian (Thai) – Tree spirit
- Nanom-keea-po-da (Abenaki) – Earthquake spirit
- Napaeae (Greek) – Grotto nymph
- Narasimha (Hindu mythology) – Avatar of Vishnu in the form of half-man/half-lion
- Narecnitsi (Slavic) – Fate spirit
- Nariphon (Thai) – Pod people
- Nargun (Gunai) – Water monster
- Nasnas (Arabian) – Half-human, half-demon creature with half a body
- Nav' (Slavic) – Ghost
- Nawao (Hawaiian) – Savage humanoid
- N-dam-keno-wet (Abenaki) – Fish-human hybrid
- Neptune (Roman mythology) – God of freshwater and sea
- Neck (Germanic mythology) – Female water spirit
- Negret (Catalan) – Little people that turn into coins
- Nekomata (Japanese) – Split-tailed magical cat
- Nekomusume (Japanese) – Cat in the form of a girl
- Nemean Lion (Greek) – Lion with impenetrable skin
- Nephilim (Abrahamic mythology) – Gigantic sons of Grigori and human women
- Nereid (Greek) – Nymph daughters of Nereus
- Ngen (Mapuche) – Nature spirit
- Nguruvilu (Mapuche) – Fox-like water snake
- Nian (Chinese) – Predatory animal
- Night hag (Worldwide) – Supernatural creature, commonly associated with the phenomenon of sleep paralysis.
- Nightmarchers (Hawaiian) – Warrior ghosts
- Nikusui (Japanese) – Monster which appears as a young woman and sucks all of the flesh off of its victim's body
- Nimerigar (Shoshone) – Aggressive little people
- Ningyo (Japanese) – Monkey-fish hybrid
- Ninki Nanka (Western Africa) – Large reptile, possibly a dragon
- Nisse (Scandinavian) – House spirit
- Níðhöggr (Norse) – Dragon
- Nivatakavachas (Hindu) – Ocean demon
- Nix (Germanic) – Female water spirit
- Nobusuma (Japanese) – Supernatural wall, also a monstrous flying squirrel
- Nocnitsa (Slavic) – Nightmare spirit
- Noppera-bō (Japanese) – Faceless ghost
- Nozuchi (Japanese) – Small sea serpent
- Nuckelavee (Scottish) – Malevolent human-horse-fish hybrid
- Nue (Japanese) – Monkey-raccoon dog-tiger-snake hybrid
- Nü Gui (Chinese) – Vengeful female ghost
- Nukekubi (Japanese) – Disembodied, flying head that attacks people
- Nuku-mai-tore (Māori) – Forest spirit
- Nuli (Medieval Bestiary) – Humanoid with backwards, eight-toed feet
- Numen (Roman) – Tutelary spirit
- Nuno (Philippine) – Malevolent little people
- Nuppeppo (Japanese) – Animated chunk of dead flesh
- Nurarihyon (Japanese) – Head-sized ball-like creature that floats in the sea and teases sailors
- Nure-onna (Japanese) – Female monster who appears on the beach
- Nurikabe (Japanese) – Spirit that manifests as an impassable, invisible wall
- Nyami Nyami (Tonga (Zimbabwean) mythology) – Snake-spirit of the Zambezi River
- Nykštukas (Lithuanian) – Cavern spirit
- Nymph (Greek) – Nature spirit
