The scene in which a car is thrown over a cliff was initially intended to be far more spectacular - the car was to fly over the cliff and crash down to the ground. Unfortunately, the sling rope snapped because effects crew members neglected to remove the stoppers from underneath the car's wheels. The result was what is seen in the final film, the car slowly tumbles over the edge and becomes caught on a tree.
The $2 million budget went primarily on production costs. The clowns and visual effects were created almost entirely by the filmmakers at very little cost.
The Dickies, the band who wrote and performed the film's theme song, had actually not seen the film prior to writing the song.
Though not a hit when it was in theaters, the film has since become a cult classic and made revenue in action figures, DVDs, and t-shirts as well as an assortment of animatronics and other decorations from Spirit Halloween.
Originally, Klownzilla was supposed to be made with stop motion animation. But due to production costs and limited time to shoot, they made a suit instead.