Art the Clown is back! Or, is... in his first outing! Depends on where you put the previous Damien Leone shorts in the hierarchy, but Terrifier is a full 90 minute romp (blog post) where Art the Clown does what Art the Clown (blog post) does best. No, that is not explain his motives in the slightest.
Source: Terrifier Movie Review - Decker Shado