History
Percy Calvin was the son of Wilma Calvin, a respected biochemist who had attempted to recreate the Super-Soldier Serum for S.H.I.E.L.D.[1] Percy was forced to work for a criminal called the Pusher,[2] but he ultimately decided to help Ka-Zar stop the Pusher.[3]
Wanting to continue his mother's research, he murdered his mother in order to lure Mockingbird, who possessed both the Super-Soldier Serum and Infinity Formula in her blood, and capture her for his research. His plan failed, however, and Percy was arrested by Mockingbird.[4]