How many movies have Mona Fong Yat-Wah and Moo Yuk-Fan collaborated on?

They have worked on 4 movies together! Their first movie together was Corpse Mania (1981) while their highest rated movie together was The Fake Ghost Catchers (1982). They have not worked together since An Amorous Woman of Tang Dynasty (1984). They are most known for their horror films together.