I've been watching the original Scooby cartoons from 1969 (on YouTube).... In the cartoons all of the "ghosts" are villains in disguise, & the PM Figures are the same. Underneath each ghost outfit is a regular-looking clicky; however, the clickies look like the villains-in-disguise from the cartoons! A good example of this is found in the Scooby & Shaggy set, which features the flowing white-robe kind of ghost. In the original cartoon, the villain is revealed to be a Spanish-looking man with a curly mustache; the clicky is the same. Pretty neat!
I'll post pics of some of the Figures alongside screenshots of their cartoon counterparts tomorrow.