Onyxx

Onyxx
Publication information
Publisher	Marvel Comics
First appearance	X-Men (vol. 2) #171 (August 2005)
Created by	Peter Milligan (writer) Salvador Larroca (artist)
In-story information
Full name	Sidney Green
Species	Human Mutant
Team affiliations	Chevaliers training squad [ broken anchor ] Xavier Institute X-Men-In-Training
Abilities	Superhuman strength and durability

Onyxx (Sidney Green) is a fictional mutant appearing in comic books published by Marvel Comics. He first appeared in X-Men , vol. 2 #171 (August 2005), and was created by Peter Milligan and Salvador Larroca.

Fictional character biography

As a child, Sidney Green lived in various foster homes and orphanages, unable to find acceptance because of his crude behavior and chronic bedwetting. ^[1] This was cured after his mutant abilities activated, transforming him into a four-eyed golem-like creature.

Subsequently, Sidney becomes a student at the Xavier Institute as Onyxx and joins Gambit's training squad, the Chevaliers. ^{[2] [3]} He develops a crush on fellow student Foxx, who is later revealed to be a disguised Mystique. ^[4]

Sidney is one of 198 mutants who retain their powers after the Scarlet Witch depowers most mutants on M-Day. ^{[5] [6] [7] [8]} He is killed by Wither during the Necrosha event, but is later resurrected following the establishment of Krakoa as a mutant nation. ^{[9] [10] [11] [12] [13] [14]}

Powers and abilities

Onyxx has a craggy granite body, which gives him superhuman strength and durability.

References

1. 198 Files
2. Official Handbook of the Marvel Universe A to Z #13 (April 2010)
3. Allan, Scoot (December 30, 2022). "10 Teams Gambit Has Joined In The Comics". Comic Book Resources . Retrieved February 23, 2025.
4. New X-Men (vol. 2) #35 (April 2007)
5. New X-Men (vol. 2) #38 (July 2007)
6. X-Men: Manifest Destiny #3 (January 2009)
7. Dark Avengers / Uncanny X-Men: Utopia one-shot (August 2009)
8. X-Men: Legacy #226 (September 2009)
9. Walker, Gary (June 2, 2020). "Necrosha: The X-Men's Horrific Battle With the Undead, Explained". Comic Book Resources . Retrieved February 23, 2025.
10. Brueheim, Jackson (September 26, 2020). "10 Marvel Characters Who Can Kill With A Single Touch". Comic Book Resources . Retrieved February 23, 2025.
11. Tramountanas, George A. (June 9, 2010). "X-POSITION: Craig Kyle & Chris Yost". Comic Book Resources . Retrieved February 23, 2025.
12. "House to Astonish » X-Factor #5 annotations". House to Astonish. Retrieved February 23, 2025.
13. X-Force (vol. 3) #23 (March 2010)
14. X-Factor (vol. 4) #5 (February 2021)