How many movies have Allan Quimbo and Celso Ad. Castillo collaborated on?

They have worked on 1 movie together! Their first movie together was Ang Pinakamagandang Hayop sa Balat ng Lupa (1996) and was their highest rated movie together. They have not worked together since Ang Pinakamagandang Hayop sa Balat ng Lupa (1996).