Randall Peltzer, a struggling inventor, visits a Chinatown antique store in the hope of finding a Christmas present for his son Billy. In the store, Randall encounters a small, furry creature called a "mogwai" (Cantonese: , "devil"). The owner, Mr. Wing, refuses to sell the creature to Randall. However, his grandson secretly sells the "mogwai" to Randall, warning him to remember three important rules that must never be broken: do not expose the "mogwai" to light, especially sunlight, which will kill it; do not let it come in contact with water; and above all, never feed it after midnight.