I just spotted John Cherry is selling the design artwork for the memorable trolls, mostly seen toward the end of the movie Ernest Scared Stupid. The prices range from $200-$500 for a framed piece on the Ernest P. Worrell Official Shop . There are 20 pieces and it will be interesting to see how they sell. They include notes like "Disney said there was too much snot going down [his] lips" and names for the trolls.
The costumes, masks and effects were done by the Chiodo brothers special effects artists. This article shows how a couple of the masks were repurposed from the movie Killer Clowns from Outer Space made a couple years earlier. They also did the Large Marge claymation for Pee-wee's Big Adventure-- very cool!