Isbisa is a fictional supervillain in the Marvel Comics universe. He first appeared in All Winners Comics vol. 1, #19 (Fall 1946), published by Marvel predecessor Timely Comics during the 1940s period fans and historians call the Golden Age of Comic Books. He was created by writer Bill Finger and one or more of the five artists who contributed one or more chapters to his 44-page debut story. Isbisa was a criminal mastermind as well as an expert in chemistry and radioactivity.