Tanya Sealy was born in Chicago. A former call girl, she was chosen under unknown circumstances by Roxxon Oil Company to partake in a covert operation to retrieve the mystical Serpent Crown. The executives at Roxxon had a device surgically implanted in Sealy's brain which granted her superhuman abilities. Working together with three other snake-themed villains, Sidewinder, Anaconda, and Death Adder, she became a founding member of the Serpent Squad. During her first mission, Black Mamba nearly overcame the Fantastic Four's Thing, but was defeated. She also encountered Iron Man while searching for a powerful weapon known as the microscanner.
Invited by Sidewinder to join his criminal organization, the Serpent Society, Black Mamba accepted. Before working with Roxxon, she was a call-girl, and while the money was satisfying, it was not a steady income, so she jumped at the opportunity to earn vast amounts of money with Sidewinder. While in the Serpent Society, Black Mamba gained great friendships in Diamondback and the Asp, and also became romantically involved with Sidewinder. During Viper's infiltration of the group, Black Mamba stood loyally with Sidewinder, which Viper was ready to kill her for. When Diamondback turned over a new leaf, it sparked something in Black Mamba. She joined her friends Diamondback and Asp in forming BAD Girls, Inc. and worked several mercenary-for-hire missions. She also briefly served in Superia's all-female group, the Femizons, but betrayed the group to aid Captain America and Paladin. Regardless, she was a villainess and was not above committing evil acts, such as when she led a drugged Hercules to be ambushed by the Masters of Evil.

For some time, Black Mamba served in Crimson Cowl's Masters of Evil in hopes of a large profit, battling the Thunderbolts. She eventually went back to the Serpent Society for a very short time,and then left to be with Diamondback and Asp and continue to do missions as the B.A.D. Girls. During one mission, to find the "Dominus Objective," Black Mamba severely embarrassed Deadpool when she revealed his darkest fantasy—to give a back massage to his partner in crime, Cable (although her power similarly affected everyone she used it on in this appearance).[volume & issue needed] She also fought Luke Cage and Iron Fist, and was shocked to realize her group had been hired by Cable himself.