Seymour Krelborn is a nerdy orphan working at Mushnik's, a flower shop in urban Skid Row. He harbors a crush on fellow co-worker Audrey Fulquard, and is berated by Mr. Mushnik daily. One day Seymour finds a very mysterious unidentified plant which he calls Audrey II. The plant seems to have a craving for blood and soon begins to sing for his supper.

In ancient times, a man named Claus, who delivers toys in his small village, fulfils his destiny to become Santa Claus after meeting an expert toy-making elf, Patch, in the North Pole. In the present day, Santa Claus has become overwhelmed by his workload, and the disgruntled Patch flees the workshop to New York City. There, Patch unknowingly threatens the fate of Christmas by taking a job at a failing toy company run by a scheming businessman.