Diamondback (Rachel Leighton) is a fictional character appearing in American comic books published by Marvel Comics. Originally a super villain who was part of the Serpent Society, she was first introduced in Captain America #310 (October 1985) and became a series regular for years afterwards. Rachel Leighton made her debut as part of the Serpent Society and soon came into conflict with Captain America as the group carried out an assassination. Later on Leighton started to develop feelings for Captain America, drawing her away from the Society to the side of the good guys. After Captain America helped foil a takeover by Viper the two began to date. Because of her involvement with a super hero the Serpent Society voted to execute her, but her life was spared by her friends in the Serpent Society. Leighton, along with Black Mamba and Asp, formed BAD Girls, Inc. a trio of adventurers who would on occasion aid Captain America. During the "Civil War" story-line BAD Girls, Inc. sided with Captain America's Anti-Registration group. She later became an agent of S.H.I.E.L.D., before returning to her criminal roots as part of Serpent Solutions.