A young boy named Karl Berger (a surname given in the sequel) murders his abusive mother with a meat cleaver, after she beats him for returning home late. Twenty years later, in the mid-1970s, the imprisoned Karl is being transported to an unspecified location by the police, but manages to kill his captors and escape into the wilderness, somehow acquiring a cleaver in the process. Over the course of several days, Karl commits a series of murders across the countryside, mutilating and occasionally cannibalizing his victims. After one double homicide, Karl faints and has a flashback to the day he murdered his mother, revealing he had been coerced into killing her by a demon (which a line of dialogue indicates may be his father) he had encountered in the cellar after being locked in it.
At one point, Karl also encounters an apparition of Jesus crucified in the forest, which he hacks open, and crawls inside. After this encounter, Karl commits an additional dual murder outside a church, then collapses in a field, where his skin (which had been inexplicably decaying throughout the film) rots off, and he dies ripping himself open, revealing a baby covered in blood.
Source Page – Wikipedia