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.
- His name, Harley Street, is a reference to the real life street in the Marylebone district of London, United Kingdom, which has historically been the home of a large number of private specialists in British medicine and surgery since the 19th century.