The Muppet Show (1976)

Mark Hamill - S4-E16

Revealing mistake: When Luke Skywalker is introducing his 'cousin' Mark Hamill at the end, you can tell it's a split screen by the fact that Luke looks right past him, even once he's on stage. (00:25:10)

Xofer

Statler: You know I never liked this show's theme music.
Waldorf: Niether did I.
Kermit: You promised.