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.