Timothy Mulrooney was a student in Professor Jordan‘s class and would often give the teacher a hard time. One day Tim was kept after class for misbehaving and it was then that Professor Jordon showed the young student what he’d been working on. It was a chemical he called Wonder Fluid and when the solution touched his skin the Professor was changed physically. It was soon after that he put on a costume and dubbed himself Captain Wonder not long after Tim accompanied him on his outings to fight crime as his sidekick.