Watch Fmovies. In this campy throwback to 1950s monster films, a vicious monster, the Riverbeast, has arisen from its watery lair to terrorize a peaceful New England town. Local tutor Neil Stuart has seen the beast before, but nobody believed his story, making him the town laughingstock. Neil sets out to not only prove that the Riverbeast exists, but also, with the help of his beautiful pupil, scrappy tutor buddies, and a former professional athlete, to vanquish the aquatic menace!