A city doctor and his pregnant wife go to the ultra-busy woods of Maine to tend to all the sick Native American kids covered in pine cones and sores that won’t heal. Mercury poisoning, it’s discovered, is behind the face herpes.
The doctor discovers the saw mill has been polluting the local waterways with Mercury-based chemicals used to make logs all nice and shiny. Fish swim in that water. The fish mutate. The local Native Americans eat the fish. The Native Americans mutate.
Evidence to this outlandish claim lies in a horribly disfigured baby bear cub, found almost drowned to death. Unfortunately, it’s a long way back to camp and horribly disfigured mama bear is looking for her crusty kid. But she’s been busy, killing sleeping bag campers as though they were foreign tourists. Ripped, shredded, half-eaten, mangled, chewed, regurgitated… It was if they were human snack cakes at the last Drinkin’ & Drive-in Bake Sale.
Plenty of great moments, but the best comes when the monster bear chases them across a lake and goes into the drink in an iconic horror movie sequence. Thinking that gosh-darned thing drowned, they don’t see the bubbles heading towards shore. The bear walks all the way under the lake without scuba gear or anything resembling a snorkel!
No matter what they throw at mom, it still keeps coming. She looks like a reverse bear with melted skin and gut stuff on the outside where fur should be. Prophecy (1979) is loaded with gnarly nature-gone-awry action that sets you up for a sequel (pregnant mom has been eating the tainted fish).
They never made another movie, though. Too bad; I felt Underwater Bear deserved to be been fleshed out a bit more. Oh, hey — I just got my own joke. Sweet!