Heckle and Jeckle are postwar animated cartoon characters created by Paul Terry, originally produced at his own Terrytoons animation studio and released through 20th Century Fox. The characters are a pair of identical anthropomorphic magpies who calmly outwit their foes in the manner of Bugs Bunny, while maintaining an aggressively mischievous streak reminiscent of the early Woody Woodpecker or Screwy Squirrel.
Unlike Bugs Bunny, their comic aggression is often unprovoked, and in a number (perhaps most) of their cartoons (Moose on the Loose, Free Enterprise, The Power of Thought, Hula Hula Land) their foes win in the end.
According to Leonard Maltin's Of Mice and Magic: A History of American Animated Cartoons (1980) and Don Markstein's Toonopedia, Paul Terry considered the Heckle and Jeckle series the best cartoons his studio ever made.
Although identical in appearance, they are differentiated by their voices. Jeckle speaks with a slightly falsetto English accent, and his dialogue is somewhat more refined. Heckle is more rough around the edges, and speaks with a more informal, slangy vernacular and gruff New York dialect.
However, the two magpies are far more alike in temperament than they are different. The characters seldom referred to each other by name, leading to some confusion as to which one was which.
Heckle usually refers to Jeckle familiarly, as "chum" or "pal", while Jeckle often calls Heckle "old chap", "old thing", "old boy" or "old featherhead", indicating a close friendship between them.
Both characters were voiced at different times by Sid Raymond (1946–47), Ned Sparks (1947–61), Roy Halee (1951–61), Dayton Allen (1956–66) and Frank Welker (1979–81).