Butch is a Bengal tiger who made various appearances on Sesame Street. He was the first Muppet designed and built by Ed Christie, and originally appeared as a saber-toothed tiger (performed by Brian Muehl) in the "Toothbrush" sketch of the Caveman Days series. The puppet was also used on The Muppet Show, starting in season 4.
The tiger was named onscreen in episode 416 (performed by Jim Henson), when he teamed up with a lion as "Butch and Sundance", running away from an animal training act. (This is a reference to the 1969 film, Butch Cassidy and the Sundance Kid.)