The Ultimate Book of Spells (2001)

S1E12 Out of Shape

Zarlak has managed to capture tiny creatures known as "the tricky trolls," but one manages to slip away and seeks refuge with the kids. In response, Zarlak dispatches his dragon to snatch their magical book, but instead, it captures Verne, who has transformed into UBOS. They then kidnap Gus, leaving Cassy to step up and rescue them. However, she struggles with her shape-shifting abilities. Can she successfully transform into Zarlak and turn the tide in their favor?