When Dennis and the gang think they have caused Ralf to lose his job, they're determined to make his last day at Bash Street School totally blam by setting up the greatest prank Ralf's ever known.

When Walter leaves his pampered pet croc, Crunchzilla, to fend for itself, Dennis and the gang help him to get in touch with its wild side. Walter does his best to prevent them, as he needs to keep the croc tame in the hope of getting back his father's limo keys, which Crunchzilla has accidentally swallowed.