Quick recap
Evan Ross, punished for telling tall tales at school, is cleaning the class hamster Cuddles' cage when his friend Andy shows up with a can of Monster Blood. She secretly feeds some to the hamster, which swells to ten feet tall and wrecks the classroom. To fight it, Evan swallows goo from his locker and grows to match, but he stops growing and loses the wrestling match, since the hamster is much heavier. Both shrink back when the goo's expiration date passes that same day. Teacher Mr. Murphy gives Cuddles to Evan. That night, Andy turns up with a German can of Monster Blood, and Cuddles is eating something.
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