Dr. Street is a brilliant astronomer working for MASA. He was in charge of the Kat Sat 1 project. Unfortunately for him, when his satellite returned, it was coated with a sticky slime containing an alien Ci-Kat-A, which bit him, taking control of his mind and eventually mutating him into a Ci-Kat-A-like creature himself. Dr. Harley Street tried to help the alien queen to achieve its full power by letting her eat the radioactive material from Megakat Nuclear Power Plant. He was supposedly killed when he was thrown out of the Megakat Tower by Razor. He only appeared in The Ci-Kat-A," but was supopsed to appear in the unfinished episode "Doctors of Doom" where Dr. Harley Street resurfaces and teams up with Dr. Viper to create havoc in Megakat City. He was voiced by the late Robert Ridgely in the original English version and by Takeshi Kusaka in the Japanese dub.