Addams Family Values hits the ground running by introducing a new member to the household: Pubert, a mustache-sporting baby boy. The arrival of the new infant instantly triggers the homicidal jealousy of older siblings Wednesday (Christina Ricci) and Pugsley (Jimmy Workman).

To protect the infant, Gomez and Morticia hire a nanny, Debbie Jellinsky (Joan Cusack). Unbeknownst to the lovesick Addamses, Debbie is a notorious serial killer known as the "Black Widow," who marries wealthy bachelors and murders them for their fortunes. Her next target? The wealthy, naive Uncle Fester (Christopher Lloyd).