Place this clip right after the punchline or failed attempt, as the reaction beat before the scene moves on. Follow it with a funny ha ha laugh if the joke needs a bigger crowd feel, or lead in with a ba dum tss drum sting for a tighter setup.
About this sound
This is a short 3-second clip of Mordecai and Rigby laughing together in their high, wheezing cartoon voices, the two of them setting each other off. It feels goofy and contagious, like an inside joke you walked in on halfway through. The laugh comes from Regular Show, the animated series built around the pair's slacker antics.