How many movies have Don Messick and William E. DeBoer collaborated on?

They have worked on 1 movie together! Their first movie together was Yogi's First Christmas (1980) and was their highest rated movie together. They have not worked together since Yogi's First Christmas (1980).

Role
Boo Boo / Ranger Smith / Herman the Hermit (voice)
Crew
Negative Cutter