Prankster
From superman.nu: Supermanica
Prankster, The. The so-called "clown king of the underworld" (S No.69/1, Mar/Apr 1951: "The Prankster's apprentice!"), a "cunning" and "ruthless" criminal with "a dangerous sense of humor" (S No.50/2, Jan/Feb 1948: "The Slogans that Came Too True!") who is forever playing pranks on people, including his own henchmen (Act No.104, Jan 1947: "Candytown, USA"; and others), and who likes nothing better than to pull an uproarious prank-filled crime while at the same time making a monkey out of Superman (S No.55/1, Nov/Dec 1948: "Prankster's Second Childhood"; and others).