Viper (real name Ophelia Sarkissian) was a mutant with the ability to generate toxins and regenerate her skin.
Viper was a cold and calculating mutant, who cares little for anyone but herself. She was shown to be completely ruthless in getting what she wants and was willing to kill for it, having no problem with poisoning a stranger who insulted her. She is a brilliant scientist who specializes in biochemistry and genetics.
Viper was seen tending to Ichiro Yashida before Logan proceeds to converse with him. While examining the medical room, Logan notices a glass container full of nanobot-like machines. Later, Viper infects Logan with one of the machines; the bot latches onto Logan's heart, shutting down his healing factor. When Viper goes to hunt Logan and Mariko, she encounters Harada scowling him and telling him that he had utterly failed to fulfill Yashida's dying wish.
As Shingen Yashida prepares to kill Mariko, Viper and Harada intercept the two, capturing Mariko as Viper poisons Shingen. Later, Viper restrains Logan who reveals to him her plans to extract his healing factor and introducing him to the Silver Samurai, a powered exoskeleton constructed out of adamantium. Harada shoots Viper with an arrow, who instead regenerates her skin and proceeds to engage Yukio. After a vicious fight, Yukio manages to strangle Viper with a wire and suspends her before kicking down the elevator switch, causing the counterweight to collide with Viper's head, killing her instantly.
Powers and abilities
Toxin immunity: As stated by herself, Viper was immune to all worldly poisons and toxins, which includes (as Viper puts it) the toxin of man.
Venom: Viper can spit out a lethal venom that can cause extreme pain and death. She can either breath the toxin, pass it on by kissing, or by using her tongue to secrete it on her claws. If the toxin is blown then it will only take effect if it enters an open wound.
Claws: Much like Victor Creed, Viper can elongate her fingernails and use them to slash at her enemies. She can also secrete them with her toxin from her tongue to poison her foes.
Regeneration: Viper can heal her injuries by shedding her wounded skin, as evidence when Harada shot her with an arrow. When she shed her skin, her hair also goes with the old skin.
Agility: Viper had natural snake-like agility that allowed her to dodge Yukio's sword strikes with ease.
