|Voiced by:||Mark Hamill|
|Appears in:||"The Power"|
The Moon Monster is a creature that appears in "The Power" as the antagonist of that episode.
In "The Power", Rigby sends several items to the moon, including "a bunch of baby ducks" (which resemble the ones from the episode "A Bunch of Baby Ducks") and "a soda machine that doesn't work" using The Power. He also sends the Moon Monster there. The monster proceeds to attack Skips, until Rigby uses "hamboning" to avert the crisis and save him. After Rigby escapes, the monster runs after the gang but was not able to kill them due to Skips fixing the power just in time for them to be able to teleport back to Earth. His fate is currently unknown, but he could still be living on the moon and might be seen again if they travel back to the moon.
The Moon Monster is very large, and has Rigby's body, Mordecai's tail feathers, and Beef Burrito's head. He also wears a belt with a golden belt buckle, somewhat resembling the one on the Beef Burrito doll.
- He is the first antagonist of Regular Show, as he was in the first episode, "The Power".
- In the credits for "The Power", he was credited simply as "Monster".
- The Moon Monster appears in the game from Cartoon Network: Escape From The Moon which is featured in Just a Regular Game.
- Even though the Moon Monster has Beef Burrito's head, he doesn't have his mustache, but in the original drawing, he had a beard.
- He didn't appear in Exit 9B likely due to not having been dead.