Apparently, Alan Newman was a huge Dungeons and Dragons fan. He was knee-deep in a hair-raising campaign with his 7th level druid named Krenzle when he came upon a huge overgrown bog (played out with old-school figurines, mind you). Krenzle apparently razed the bog, also known as a ferndock, and found the Cloak of Invisibility!
They put it on hats.