Big Wolf on Campus (1999)

S3E10 Very Pale Rider

Merton’s fantasy role-playing game suddenly becomes terrifyingly real when he gets pulled into another dimension and faces an actual fire-breathing monster. Terrified, he escapes back to his own world and rushes to get help from Tommy—only to find Tommy acting like a peaceful Gandhi. The monster, a Shederack, follows them into Pleasantville. Now Tommy and Merton must destroy it before it lays waste to the town—and before it can return to Ursula’s dimension to seize control.