Wicked Science (2004)

S2E11 Koala in the Mist

Toby and his pals stumble upon a koala, but Garth's foolishness results in Jack getting hold of an enlarging ray. Chaos ensues when the koala grows to giant size, wreaking havoc throughout the school, all while Toby inadvertently conjures a mysterious mist. As the pandemonium unfolds, will Toby and Elizabeth’s hidden truth be revealed? And will Jack confront his growing doubts?