Muscle Man is a green man with shoulder-length, greenish-brown hair. He is also fat and has large breasts. He wears a long-sleeved grayish-blue shirt, dark gray pants, and black shoes. In ""Under the Hood"," it is shown that he wears socks, but the pants cover them. In ""Trucker Hall of Fame"," when he was a kid, he still looked the same, but with freckles. As a teenager, he was tall, and had zits. It is unknown how he acquired his green complexion. He is 5"8 shown in the the book of the park workers and their jobs that appeared in "Exit 9B".
In "Power Tower," it is revealed that he was in fact very musclar in his youth, but let himself go as years went by (Mordecai and Rigby admit they assumed the name "Muscle Man" was ironic). However, while he is extremely out of shape, it is shown that he still possesses excellent body-builder posing technique, including the ability to pull of the deadly pose "The Shredder."
Muscle Man is a human that works in the park along with Mordecai and Rigby. He is also quite unhygienic, reeking of body odor as evidenced in "The Night Owl". As of the episode "Gut Model", he has worked for the park for 5 years. Benson considers him to be hard-working, and indeed, Muscle Man (along with Hi Five Ghost) has been revealed to do more work than Mordecai and Rigby, the fact is all four of them are slackers. In fact, in "Muscle Woman", they tend to slack off more than Mordecai and Rigby. In "My Mom", it's shown that he has a lot of friends, most in which love his constant "My Mom!" jokes, which everyone else at the park gets annoyed with. He's best friends with Hi Five Ghost, who loves his jokes. Ignorant yet clever when it comes to pranks, he's always either insulting Mordecai or Rigby, or trying to prank them (ex. "My Mom", "See You There"). But he does care about his mom as shown in "My Mom" when he got very angry when Mordecai and Rigby made fun of his mom. In response, he brought his brother, John, to give Mordecai and Rigby a punishment for ridiculing their mother. Their punishment was them to say sorry to their mom, (which was muscle man's butt squished together to look like a womans face) kiss the photo and eat it.
Despite being obese and lazy, there is a story behind Muscle Man's nickname (as revealed in "Peeps"). In the episode, he said that he is losing muscle mass from the stress Peeps put on him, so he may have muscle mass. He also loves to mess around with Mordecai and Rigby.
Muscle Man has developed a massive ego that is seen throughout the series especially in "Exit 9B", where he purposely has the biggest signature.
In "Out of Commission", he got 70% of his butt covered in 3rd degree burns.
In Regular ShowEdit
Starla is Muscle Man's girlfriend that is seen in "Muscle Woman". Muscle Man has been dumped by Starla twice, presumably for not being willing to share his feelings. However, by the end of the episode, they are back together and are still in a relationship. Starla has had many relationships with men. In "Fancy Restaurant", Starla is still seen as being Muscle Man's girlfriend, and invites him to have dinner with her parents. At the end of the episode, Muscle Man, Starla, and Starla's parents eat dinner at Wing Kingdom. In "Bald Spot", Muscle Man worries that Starla will break up with him for being bald, but in the end they are still together.
Hi Five GhostEdit
Hi Five Ghost is to Muscle Man as Rigby is to Mordecai. They are usually seen together in the episodes. He is the only one in the gang who appreciates Muscle Man's 'My mom' jokes. In "My Mom," the two seem to slack-off as much as Mordecai and Rigby.
Out of the two protagonists, Mordecai seems to dislike Muscle Man more. He is annoyed by the constant "My Mom" jokes and even confronts Muscle Man about it in "My Mom" Besides that episode, there is not much interaction. Muscle Man does throw his shirt at Mordecai in "Caffeinated Concert Tickets," but that may have been an accident rather than a direct confrontation. He may have been doing this just so that they would not have to do his work. In Season 3, they become nicer and friendlier to each other, help each other with problems and Mordecai even tells Muscle Man that him and Rigby are his friends in "Fancy Restaurant," after offering to help him. In "Trucker Hall of Fame ," Muscle Man tells Mordecai and Rigby that he considers them close friends, and that he pranks them because that's how he grew up. However, Mordecai and Rigby are asleep at the time, and do not hear this. Muscle Man has often turned to Mordecai and Rigby for help when he has a problem involving Starla, and has given Mordecai advice on dealing with his crush on Margaret. He's also helped Mordecai and Rigby on occasions, such as getting the word out about their party for Margaret in "T.G.I. Tuesday" and training them to spin donuts in "Carter and Briggs."
Rigby seems to like Muscle Man slightly more than Mordecai. He likes to hang out with him in "My Mom," and seems to get along with him very well, yelling "Ohhhhhh!" along with him at the taco truck. They do have some confrontations though. In "Meat Your Maker," he goes to say Muscle Man pushed him at a party (though Mordecai quickly says Muscle Man was not even there). By the end of "My Mom," Rigby goes on to say how he hates Muscle Man. In "Death Punchies," Muscle Man is forced to be look out, even though his eyes were punched out by Rigby. They also hang out in "The Night Owl." In Season 3, Rigby and Muscle Man become more friendly to each other and at times help each other with problems. In "Bad Kiss", Rigby, after learning Mordecai kissed Margaret, said that he owes Muscle Man a lot of money. Although with the alteration in time caused by Mordecai and Rigby, the kiss never happened and the bet is still on, or at least was until Picking Up Margaret. Muscle Man and Rigby have yet to learn of these events.
Benson trusts Muscle Man far more than Rigby and Mordecai, as established in "Appreciation Day" and "My Mom." He does fire Muscle Man though in "Don" and "Under the Hood." Benson also seems to understand Muscle Man and his antics, as demonstrated in "But I Have a Receipt" and "Free Cake," not yelling at Muscle Man when he put "My Mom" on the list. He does not confront Muscle Man when he turns off the lights and unzips his pants in "Free Cake," simply saying, "It's not that kind of party, Muscle Man." In season 3, he started to get a little annoyed with him. But Benson yells at Muscle Man for the first time in "Firework Run" (which was in season 4)
They do not talk much in the series but seem to be good friends. Like in "Under the Hood," he gives Skips saucy chicken wings from Wing Kingdom and in "The Christmas Special" he complimented Skips on how good his Christmas cookies were and tells him about a bakery Muscle Man goes to.
Pops tries to help Muscle Man to learn how to be fancy, but he fails, in "Fancy Restaurant." As shown in "Prankless," he greatly respects Pops because when he was going to prank Mordecai by putting his bed on the ceiling, it fell on Pops and he nearly died, thus Muscle Man said that he would never prank again until Benson convinced him.
Margaret and Eileen have only ever interacted with Muscle Man once in "Do Me a Solid," when Eileen, Margaret, and an uninvited Muscle Man were having Ice Cream Sandwiches at Mordecai and Rigby's house. They do interact with Muscle Man and Starla in "The Longest Weekend", plus helped Starla while she was going through relationship withdrawals throughout the episode.
Thomas usually gets picked on by Muscle Man,as shown in "Starter Pack" and "Terror Tales of the Park II". Although at the end of "Starter Park" when both Thomas and Muscle Man were involved with a prank against Mordecai and Rigby, that was possibly the only seen time that Muscle Man wasn't being antagonistic towards Thomas. While it is uncertain whether they're friends or not, but Thomas did help Mordecai, Rigby, Skips, High-Five Ghost, and Pops while Muscle Man was going through Starla withdrawals in "The Longest Weekend".
Story of Joining Sora's TeamEdit
When Mordecai and Rigby were doing their daily work on the park, they were the first two to notice the flashing ripples in their world as Heartless appeared, but they didn't know that they came for them. When the ran to the house, Benson and the others were in the middle of poker, and after they were told about monsters, they began to prepare before the Heartless came. When Muscle Man, noticed a Snow Man(Olaf) in the middle of summer fighting against the monsters with a "hot babe", which made the gang fight along side her. When the fight was over, and before the guys could ask her out, Olaf told them that she already has a prince charming, and it was Sora (or so he thinks) which gave them a shock, and with disappointment, but after she asked them if they'd help, they quickly agreed to help her with their mission. After spending the night in the house, the Keyhole appeared out of Mordecai and Rigby's game system. When the group appeared when they heard the Keyhole making a loud "shing" sound, they saw Elsa calling Sora from the Gummi, and seeing him appear from a portal. After Sora opened the new pathway, they were surprised with more shock as they saw the two hug, so they asked to join the team to save their world (but also be close to Elsa).