I originally saw this this illustration by Les Edwards in Omni magazine (I think), and then again in a collection of illustration that I bought in about '83 (I think).

I found it immensely evocative then, and still do. It would make an excellent setting for a megadungeon-based campaign.

Grass tufts from false eyelashes

I don't know who came up with this idea, but it is genius and I'm definitely going to try it out.