Muscle Man is one of the groundskeepers at the park. He is almost always seen hanging out with High Five Ghost, as they get assigned jobs together by Benson. Neither Muscle Man nor High Five Ghost seem to live in Pops's house, although it is most likely they live on another property somewhere in the park. Muscle Man is a fan of Fist Pump, along with Rigby. He also has a habit of taking his shirt off and twirling/throwing it. He appears to be the party type and enjoys "getting naked" as seen in Free Cake. It is shown that Muscle Man sometimes does tend to annoy Benson and feels great about it, as seen in Don. He frequently uses the term "My mom!" as a response, which tends to make Benson very angry. He seems to be one of the minor groundskeepers, only in his 30s or late 20s. However, despite Muscle Man's annoying attitude, he is really trusted by Benson, even though he and High-Five Ghost tend to slack off more than Mordecai and Rigby do. It is revealed he has a brother and an uncle in "My Mom". Muscle Man mistakes Mordecai and Rigby for making fun of his mom. Though, he was probobly kidding about thinking Mordecai and Rigby hated his mom.
He, along with High Five Ghost, appeared in numerous episodes and they both got a Gemmy and a Lobscar Award along with different characters.