bastard sequel
A sequel of a book or movie made for the sole purpose of cashing in on the name of the first one. Is generally done with no input from the original author/creator. Usually bastardizes the characters and butchers the story of the original.
Examples of bastard sequels include Rurouni Kenshin: Seisouhen, Anne of Green Gables: The Continuing Story, Scarlett, Terminator 3: Rise of the Machines and Return to the Secret Garden.