How many movies have Janet Waldo and Joseph Barbera collaborated on?

They have worked on 8 movies together! Their first movie together was Alice in Wonderland or What's a Nice Kid Like You Doing in a Place Like This? (1966) while their highest rated movie together was Scooby-Doo Meets The Addams Family (1972). They have not worked together since Scooby-Doo's Spookiest Tales (2003). They are most known for their animation films together.