Hop's Wooloo debuted in Letter where it was seen playing with Hop.
Wooloo had a bigger role in Buddy, when it ran off on its own after watching Leon's match on television with Hop, since it is dissatisfied with its only moves Tackle and Defense Curl and wanted to prove to Hop that it can be as strong as Charizard. When it was wandering around town, it accidentally irritated a Yamper. It later attempted to imitate a Charmander breathing fire, but attracted unwanted attention from some enthusiastic girls. When it saw a ramp, it decided to imitate Charizard's flying, but ended up crash-landing at Milo's farm. At first, Wooloo was reluctant to be sent home by the cab driver, until Corviknight frightened it, which made it comply. Sinking at the cab seat, Wooloo recalled how the other Pokemon it came across all had loving trainers, and noticed its own friendship bracelet that Hop made specially just for it, thus beginning to sob. Suddenly, it heard Hop desperately calling out for it, and realizing that Hop was genuinely apologizing to it and wanting to venture to the Pokemon League with it, it finally knew that Hop had cared for it greatly and leaped into his arms with tears. It was last seen snoozing inside the cab with Hop when they were being sent back home.