Running Gag

A joke whose humor derives from repetition, ideally becoming funnier each time it is repeated. Must be repeated at least three times, otherwise it's a Brick Joke.

Kermit the Frog: No, Fozzie! Do not answer that telephone!
Fozzie Bear: But, Kermit, all these terrific, funny things happen when I do answer it!
Kermit: I'm aware of that! I'm aware of that, Fozzie! Is there no end to this running gag?!
— The Muppet Show