The Borogoves are birds on stilts that appear in The Muppet Show Episode 506. The Borogoves, the Slithy Toves and the Mome Raths are characters from Lewis Carroll's poem "Jabberwocky", which is performed in the episode by Rowlf and Scooter. A Borogove appeared before this appearence in Episode 424, where he had no long feet, but wings.
A Borogove also appears in Debbie Harry's "One Way or Another" number in Episode 509. One also appears in Jean-Pierre's dresssing room, along with other birds, in Episode 510.