He appeared in episode 414's UK Spot on The Muppet Show, "Pass That Peace Pipe," singing with Muppy, Baskerville and the Wolfhound. He also appeared in "The Cat Came Back" in episode 523 (where he was performed by Richard Hunt), and elsewhere.
On The Jim Henson Hour, he appeared as the All-Dog Network announcer in "Dog City," performed by Dan Redican. He would later appear in that episode's spin-off series, Dog City as Colonel Claghound in "Of Mutts and Mayors" and in "No Pain, No Brain" as an exercise coach.
Other appearances included Country Music with the Muppets (where he's performed by Frank Oz, and requests Loretta Lynn), The Muppets at Walt Disney World (with Rowlf and other dogs in the pet detention center) and the films The Muppet Christmas Carol and Muppet Treasure Island.
Lyle was named in honor of his designer/builder, Lyle Conway.