Onyxx

Onyxx (Sidney Green) is a fictional mutant appearing in comic books published by Marvel Comics.

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

Publication history

Onyxx first appeared in X-Men (vol. 2) #171 (August 2005), and was created by Peter Milligan and Salvador Larroca.

Onyxx was killed by Wither during the 2009 event Necrosha. In a 2010 interview with Comic Book Resources, Necrosha writer Christopher Yost stated that he disliked Onyxx and intended to kill him off earlier, but was stopped by editorial mandates.^[1] Onyxx returned during the Krakoan Age in 2021, having been resurrected by the Five.^[2]

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.^[3] This condition is cured after his mutant abilities activate, transforming him into a four-eyed golem-like creature.

Onyxx becomes a student at the Xavier Institute, assigned to Gambit's training squad, the Chevaliers.^[4][5] Onyxx has a romantic interest in a new student at the Institute by the name Foxx. It is later revealed that Foxx is a disguised Mystique, who infiltrated the school to destabilize the relationship between her foster daughter Rogue and Gambit. Mystique escapes and injures Onyxx.^[6]

Decimation

Onyxx is one of 198 mutants who retain their powers after M-Day, when the Scarlet Witch removes the powers of most mutants on Earth. He continues to live at the Xavier Institute.^[7]

Onyxx, along with fellow students Mercury and Loa, is tasked with keeping peace in Telegraph Hill, San Francisco after the mutant-hate group "Humanity Now!" marches from Sacramento to San Francisco to promote "Proposition X". After the riots subside, Cyclops comes and picks the three up, taking them to City Hall.^[8] He is also seen in the company of Ariel when she arrives to pick up an injured Trance.^[9]

Necrosha

In Necrosha, Onyxx is seen amongst those under attack by Selene's new Inner Circle on Utopia. Onyxx tries to sneak attack Wither, who kills him by disintegrating his body.^[10][11][12] Years after his death, Onyxx is resurrected following the establishment of Krakoa as a mutant nation.^[2][13]

Powers and abilities

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