Wallaby on Wheels is the second segment of the ninth episode of the fourth season of the series.
Rocko is at Kind of a Lot-O-Comics reading the latest issue of the Really Really Big Man comic book of what the superhero does to impress his crush. Although he immediately dismisses the story's events as rubbish, he eventually falls in love with Sheila, a skater who is one of Heffer's friends, when she purchases a comic book. The only problem is that Rocko is an inept roller skater. So to impress her, Rocko allows Heffer to teach him how to roller skate.
The two arrive at the Rool-O-Dome and Rocko struggles to get used to skating on the rink. When Shelia meets him, she asks Rocko if he would skate with her, to which Rocko agrees to. As Heffer shows off his skating prowess, a jealous Rocko decides to do something impressive by taking the obstacle course with real hazards. When he realizes how dangerous it is, Rocko soon regrets his temerity, and after completing it, he can't stop, and is on the urge to fall into the bottomless pit below the hill. So it's up to Heffer to save Rocko's life. After he does this Heffer has an accident after hitting his head on a crane and Rocko has to rescue his unconscious best friend as he uses a jackhammer he borrowed from a construction worker to jack down the hill. Luckily, the large globe of the roof of the Health Club building rolls on top of the pit and Heffer lands on top of it just in time. Sheila likes Rocko for saving Heffer and being able to use a jackhammer, as Rocko apologizes to her in return. In the end, Rocko teaches Sheila a to ride a jackhammer as Heffer falls in the bottomless pit after the large globe cracks and eventually breaks under him. Rocko learns that it's better to be himself.