Regular Show: Muscle Man

When Mordecai and Rigby fail at another task, Benson has Muscle Man and High Five Ghost supervise them. Mordecai and Rigby have to put up with Muscle Man and High Five Ghost's annoying shenanigans (including Muscle Man's "My mom!" jokes).

Muscle Man breaks up with his girlfriend, Starla, leaving him an emotional mess and unable to work. When Mordecai and Rigby are forced to pick up Muscle Man's jobs around the park, they attempt to reunite Muscle Man and Starla, until she begins to fall for Mordecai.

When Muscle Man and High Five Ghost are watching viral internet videos, Mordecai and Rigby say they can make a better video, and bet Muscle Man and High-Five Ghost $10. Muscle Man and High-Five Ghost make three videos that each get 900,000 views, and Mordecai and Rigby call it double or nothing.

Muscle Man invites his coworkers to celebrate the five years he has been at the park by going to "Fry-It-Up" (a local restaurant), but they are unable to attend due to previous engagements. (Mordecai and Rigby have dates with Margaret and Eileen, Skips, Pops, and Benson have to go lawn bowling, and High-Five Ghost has to go to his brother, Low-five Ghost's police academy graduation).

After their lunch break, Mordecai is ready to get back to work, but Rigby wishes to continue slacking off. Mordecai tries to convince him to get back to work, which makes Rigby begin to talk about how he can slack off at any time without Benson firing him.

When Muscle Man's father, Muscle Dad, dies, Benson asks Mordecai and Rigby to go along with Muscle Man to spread the ashes of his father's hat (which reads "World's Greatest Trucker") at the highest point at the Trucker Hall of Fame. While at a truck stop, three truckers tell Mordecai and Rigby that Muscle Man's dad wasn't really a trucker like he told Muscle Man when he was a kid but instead he was a forklift driver.