Jabberwock

From Muppet Wiki

The Jabberwock appeared in episode 506 of The Muppet Show, which features the Muppets' adaptation of Alice in Wonderland. During the Jabberwocky sketch, his head is lopped off, and floats for the remainder of the show.

The Jabberwock was built by Tim Miller and looked almost exactly like John Tenniel's original illustration of the Jabberwock from the book Alice's Adventures in Wonderland.