Tanya Sealy was given psionic abilities by the Roxxon Oil to be part of the third Serpent Squad. When Sidewinder formed the Serpent Society, she was one of the original members, and became romantically involved with Sidewinder.
When Viper took over the Serpent Society, Black Mamba refused to join her and remained loyal to Sidewinder. Black Mamba's powers were useless against Viper, who seemingly has never loved anybody, and she was restrained and poisoned by Viper, who gave her less than one hour to join her or die by the poison. After defeating the rest of the Serpent Society, The Captain and Diamondback gave an antitoxin to Black Mamba and the other Society members who remained loyal to Sidewinder.