Lady Serpent is the evil wench who kills. She not only strikes fear in the hearts of her gang, but also the police. Sergeant MacGooligan has a “fierce headache” caused by the Lady Serpent busting out of jail. He tells the story of her escape to Black Terror and his young companion, Kid Terror, in their civilian identities as a pharmacist and a soda jerk. The prison break ends tragically because Lady Serpent guns down the prison warden and a police detective, which gets the Terror Twins, as they are called, into action.
Black Terror had a long run in the 1940s. I counted 127 issues of comic books where Black Terror appeared between 1941, in America’s Best Comics, Black Terror, and Exciting Comics, when Black Terror's run ended in 1949.
This story is drawn by the team of Jerry Robinson and Mort Meskin, and is from Black Terror #23 (1948):