Villian(s)  Bat hybrid

Actor(s):  Stewart Moss, Marianne McAndrew, Michael Pataki, Paul Carr

Brief Description  The Bat People (also known as It Lives by Night or It's Alive) is a 1974 American science-fiction horror film produced and distributed by American International Pictures (AIP). Directed by Jerry Jameson and written/produced by Lou Shaw, the film blends classic monster movie tropes with 1970s psychological thriller elements. Notably, the film features early-career special makeup effects by future Academy Award-winner Stan Winston.

Plot:
Dr. John Beck and his new wife, Cathy, are enjoying a mountain holiday and decide to go spelunking on a guided cave tour. While wandering away from the main tour group in a cavern labyrinth, John is suddenly attacked and severely bitten by a bat. Despite the scare, the couple returns to their vacation cabin, assuming it is a routine, albeit unpleasant, injury. Shortly after the bite, John begins experiencing severe physical and psychological changes. His senses heighten dramatically—he develops acute, painful echolocation and hears high-pitched frequencies that no one else can. He soon develops an intense, unnatural craving for raw blood.

Alarmed by his rapid degradation, John visits a local physician, Dr. Kipling. Unfortunately, the medical treatments provided only worsen his volatile condition, accelerating a terrifying genetic transformation into a rabid, half-human, half-bat creature. Driven by a mix of instinctual bloodlust and a desperate desire to cover up what he is becoming, John begins slinking out into the night. He embarks on a homicidal rampage across the local community, targeting campers and random citizens. The string of brutal murders catches the attention of Sergeant Ward, a mean-spirited, arrogant local law enforcement officer. Ward grows highly suspicious of John while simultaneously making aggressive, unwelcome advances toward Cathy.

Dr. Kipling initially tries to rationalize John's behavior, suggesting that the transformation is a psychological delusion and urging him to see a psychiatrist, but the physical evidence quickly becomes undeniable. As John loses the final remnants of his humanity, Cathy discovers the horrific truth. Rather than abandoning him, she remains deeply loyal to her husband. After an intimate encounter, Cathy becomes infected with the same mutated condition. Fleeing from the authorities, John retreats deep into the original cave system to find solace and live as a beast. Sergeant Ward pursues them to the caverns but is ultimately overwhelmed and killed by a massive swarm of vengeful bats. Having fully succumbed to the infection, Cathy transitions into a creature herself and joins her husband in the depths of the cave to live out their lives among the bat population.