The slimy denizens of the Everglades organize a particularly nasty rebellion in this enjoyable entry from the "nature-run-amok" horror subgenre which favored drive-in venues of the mid-'70s. The story takes place amid the festivities honoring the birthday of crotchety, wheelchair-bound Southern patriarch Jason Crockett (Ray Milland), a chemical-industry magnate whose pesticides are responsible for much of the toxic pollution found in the swamplands. The revelry ends quickly, however, when thousands of local fauna decide to crash the party. Under the apparent telepathic guidance of the less-than-menacing swamp bullfrogs, armies of snakes, insects, and snapping turtles tear their way through the cast. Competent direction, great use of swampland ambience, and spooky sound effects help provide a suitably large dose of the creepy-crawlies.