The Burning (1981) on Netflix

Cropsy, an alcoholic, sadistic caretaker for the summer camp called Camp Blackfoot is prank-ed by a group of camp-going boys who felt it was necessary to 'get him back'. The prank goes wrong and Cropsy is left in a hospital for five years, yet to no avail Cropsy is left to go back out into the world again but this time he is a changed individual inside and outside. Cropsy, back in society again for the first time in five years, feels more than obligated to pay a visit to some individuals at a place called Camp StoneWater, just across the way from his old stomping grounds.........