In Twilight Wings,
Hop's Wooloo was often seen sitting beside
Hop watching TV. It had initally ran away to learn to fly since it was jealous of Hop's obsession with Leon's Charizard, but Hop promised he cared for it the way it was and they'd be partners forever. Later on, it evolved into
Hop's Dubwool.
In the main series, it faced off against
Pikachu just before the start of the Master Eight tournament. It was instantly KO'd by Pikachu's Iron Tail on its first move.