Harold Shapiro was a member of Easy Company under Sgt. Rock during World War II. He was an English teacher from Durango, Colorado and was named Wildman because though he was generally calm, he became a wildman in battle.
A different character, Randall Wildman, is a member of the Blackhawk Program.
Wildman was created by Robert Kanigher and Joe Kubert, first appearing in Our Army at War #113. (1961)