The Last Drive-In with Joe Bob Briggs S33E11 - Piranha

While searching for missing teenagers, novice skip tracer Maggie McKeown and local town boozer Paul Grogan stumble upon a top-secret Army laboratory conducting genetic research on piranha fish for the purpose of developing biological warfare. When the deadly eating machines are accidently released from the compound, they're soon headed downstream and consuming everything, and anything, in their path.