Original: Scooby-Doo 2: Monsters Unleashed is a 2004 film, and sequel to 2002's Scooby-Doo based on the Hanna-Barbera series classic, Scooby-Doo.
Simplified: Scooby-Doo 2: Monsters Unleased is the sequel to the movie Scooby-Doo, released in 2004 by Warner Bros./ORGANIZATION.