Tumbler

Tumbler (John Robert Keane) is a fictional character in the Marvel Universe. He first appeared in Tales of Suspense #83 (Nov 1966) and was created by Stan Lee and Jack Kirby. John Keane, as the Tumbler, is a costumed criminal acrobat. Intending to test himself against Captain America, he broke into Avengers Mansion. He easily beat Captain America in two separate struggles—although, this turned out to be the Super-Adaptoid, who had taken Captain America's form and lacked his fighting skills. The real Captain America freed himself from the Adaptoid's trap and defeated the Tumbler in combat. Later, the Tumbler was hired by Quentin Harderman as a part of the Secret Empire's plot to discredit Captain America. The Tumbler robbed a store, and...