How many movies have Joshua Pruett and Richard O'Brien collaborated on?

They have worked on 3 movies together! Their first movie together was Phineas and Ferb: Mission Marvel (2013) while their highest rated movie together was Phineas and Ferb: Night of the Living Pharmacists (2014). They have not worked together since Phineas and Ferb The Movie: Candace Against the Universe (2020). They are most known for their comedy films together.