The American movie titled Night of the Demon and directed by James C. Wasson was released in 1980 and is categorized as horror.
Key cast members of Night of the Demon include Joy Allen, Bob Collins.
The plot of Night of the Demon is: Bill Nugent, an anthropology professor, awakens in the hospital he was brought to after having been found in the woods with his face mutilated; Nugent had ventured into the wilderness in search of Bigfoot with five of his pupils, all of whom are missing. An inspector interviews Nugent, who begins his story, which starts with Carla Thomas, the daughter of one of the cryptid's victims, asking to accompany Nugent and four of his students on their expedition to find proof of Bigfoot's existence. A flashback depicts Nugent showing Carla and his class recovered footage of Bigfoot attacking a picnicking family, whose remains were never found. Bigfoot's involvement in the disappearance of the family was deemed a hoax by the authorities, who have also labeled evidence suggesting the monster's involvement in other deaths in the area fake. Carla addresses the classroom, reveals the evidence of Bigfoot's involvement in her father's murder appears to have been tampered with, and tells of one woman's account of witnessing the creature maul her lover, who was dragged from the vehicle they were having sex in, and left to die on the windshield.
That night, Nugent assures his wife that he and his companions will be fine, despite the university revoking its sanctioning of the expedition. The next day, Nugent and his group camp out at Carlson's Landing, owned by Lou Carlson, who despite previously sharing information about Bigfoot with the authorities, acts evasive towards Nugent, brushing off the professor's questions. A student bribes Carlson with alcohol, and learns about a recluse named "Crazy" Wanda, a woman supposedly connected to Bigfoot. Elsewhere, a hunter is impaled when Bigfoot throws him onto a jagged branch.
Nugent and his five companions reach a nearby town, and question the residents about Wanda, learning that she went mute after having a stillborn and deformed baby, and is the daughter of a deranged preacher known as Emmet McGinty, whose followers (rumored to be inbred, cannibalistic, and practitioners of human sacrifice) live nearby in almost total isolation. As Nugent and the other five discuss their findings, they are spied on by the sheriff, who smokes a cigarette identical to ones a student found in an ashtray in Carlson's house. The sextet reach the end of the river and set up camp as Nugent discusses a biker killed via manual emasculation nearby. In the middle of the night, the explorers are awakened by chanting, and happen upon the rumored cult (which includes the sheriff) performing a Satanic sexual ritual involving Wanda, and an effigy of Bigfoot. Nugent scares everyone off by firing a gun into the air, and in the ensuing commotion the statue of Bigfoot catches on fire.
The campers are observed by Bigfoot, and in the morning they discover that their boat has vanished, and that large footprints have been left at the scene. The group continues onward regardless, and while having sex hours later two of the students are attacked by Bigfoot, which claws the man's back. Eventually, the expeditionists find Wanda's cabin, and gain entrance by offering Wanda candy. When shown a plaster mold of one of Bigfoot's footprints, Wanda goes berserk, and locks herself in a room. To pass the time until Wanda calms down, Nugent mentions a woodsman who was hacked to bits with his own axe, and two Girl Scouts who were stabbed with their own knives. A student goes off on his own, and is killed when Bigfoot slams his face into a tree, causing the man to accidentally shoot himself.
In an attempt to get information, Nugent uses hypnosis on Wanda, who recalls her abusive childhood, and being raped and impregnated by Bigfoot as McGinty looked on in horror, convinced the beast was a demon. McGinty killed his half-human grandchild the moment it was born, and in turn Wanda set him on fire, and made it look like a suicide. Nugent digs up the remains of Wanda's offspring, which do appear to be more beast than man. Bigfoot appears, and absconds with its dead spawn as Nugent and the others barricade themselves in Wanda's cabin. Hours later, Bigfoot breaks in, and ignoring the dissonantly calm Wanda, it forces Nugent's face onto a hot stove, and butchers the others through means that include strangulation, disembowelment, throat slitting, and impalement.
In the present, Nugent begs the inspector to find Wanda and Bigfoot to prevent further deaths, and is sedated. The inspector and attending doctors discuss Nugent's tale, and deem him criminally insane..
