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The Wizard of Id comic panel.
The Wizard of Id was a 1969 pilot film, running approximately three minutes, based on the comic strip, written by Johnny Hart and drawn by Brant Parker. The strip, which launched in 1964 and remains in syndication to date, focused on The Wizard, The King, and other residents of the land of Id.
The pilot film introduced the above two characters, using puppets which closely resemble the current comic versions, with a brief cameo by the Spook, another strip regular (depicted as green).
The pilot features a painted castle set against a plain backdrop, as the King briefly discusses Id, before being confronted by the Wizard, who uttering his trademark spell, causes him to explode. The Wizard then explains, "It's a typical Muppet ending. When you can't get out, blow something up," at which point he too explodes in a puff of smoke. Then all three characters return to dance and bow to a fanfare, with the Spook making a particularly hammy exit.
At the 2003 "Muppet Rarities" event, Craig Shemin cited this as the earliest known occasion where Jim Henson created puppets based on pre-existing characters and designs.