How many movies have Gert Verhulst and Walter de Donder collaborated on?

They have worked on 21 movies together! Their first movie together was Samson & Gert Kerstshow: Het Speelgoedgeld (1997) while their highest rated movie together was Plop en de Kabouter Paashaas (2010). They have not worked together since The Big Sinterklaasshow (2018). They are most known for their family films together.