I had been experimenting, some time ago, with Great Stuff as a filler material for paper skulls. (Never give up on a bad idea.) Great Stuff, for the uninitiated, is expanding, sometimes evil, foam in a can.
To summarize, I used too much, too fast, and it expanded unevenly during the curing process. My experimental skulls collapsed as the sticky ooze did weird things, and I was left with some very scrunched up faces.
Witches, happily, often appear to have scrunched up faces. >ding!< Thus began our Witch Project.
Special thanks go out to the folks who encouraged, prodded, plagued, heckled, and otherwise nagged your old pal Spook into finally finishing the ‘Witch Project’. You know who you are.