Villain(s)  Mad scientist, Robot, undead mummy

Actor(s):  Ramon Gay, Rosita Arenas, Luis Aceves Castaneda, Luis Aceves Castañeda

Brief Description  The Robot vs. the Aztec Mummy (1958)—originally titled La Momia Azteca contra el Robot Humano—is a Mexican science fiction horror film directed by Rafael Portillo. It is notorious for being the third and final installment of a trilogy shot consecutively, meaning a massive 20 to 25 minutes of its 65-minute runtime consists entirely of flashbacks recapping the first two films.

Plot:
The film opens with a narrator explaining a past scientific experiment. Through a massive sequence of clips from the previous movies, we learn that Dr. Eduardo Almada (Ramón Gay) once used hypnotic regression on his fiancée, Flor (Rosita Arenas). Under hypnosis, Flor recalled her past life as an Aztec maiden named Xochitl (or Zoi). Xochitl was condemned to death and sacrificed after falling in love with a warrior named Popoca (Ángel Di Stefani). Popoca was buried alive and cursed to eternally guard a golden breastplate and bracelet that map out a massive Aztec treasure.

In the present day, the diabolical mad scientist Dr. Krupp, also known as "The Bat" (Luis Aceves Castañeda), has survived his apparent demise from the previous film. Still obsessed with stealing the Aztec gold, Krupp realizes he cannot defeat the supernatural strength of the undead Popoca with human henchmen. To bypass the mummy, Krupp constructs a "Human Robot" (played by Adolfo Rojas). Despite being described as a formidable machine, the robot is built from a human corpse combined with electronic parts, featuring a boxy, refrigerator-like metal torso, mesh joints, and lightbulbs for ears.

Using hypnosis to manipulate Flor once again, Dr. Krupp uncovers the exact location of the tomb. He commands his robot to break into the Aztec tomb and steal the sacred breastplate. Popoca the Mummy awakens, enraged by the desecration. The robot and the mummy engage in a slow, campy battle. The robot initially uses built-in electrical attacks to stun the mummy. However, Dr. Almada and his associate, Pinacate (Crox Alvarado), arrive at the tomb to intervene. In the chaos, the mechanical menace is distracted, allowing the furious Popoca to tear the robot apart piece by piece. Popoca then dispatches Dr. Krupp and his thugs before finally returning to his eternal slumber, leaving the treasure safe.