Where can I find this Wubbulous World character?

[Flaky Pudding]

The TVTropes page for The Wubbulous World of Dr. Seuss mentions a group of creatures that apparently were featured in Season One of the show. They were originally known as The Screaming Greebles (later changed to the Annoying Greebles) and were a species that resembled skeletons and made strange chanting sounds.

I can't find any pictures of them anywhere. I'm starting to think that maybe whoever created the TVTropes entry was making them up. If they were real, could someone please tell me where I could possibly find a picture? I've been intrigued ever since I first heard about the Greebles.