How many movies have Sven Libaek and William Hanna collaborated on?

They have worked on 7 movies together! Their first movie together was Scooby-Doo! Meets the Boo Brothers (1987) and was their highest rated movie together. They have not worked together since Scooby-Doo! and the Reluctant Werewolf (1988). They are most known for their animation films together.