Grover will be pretty much if you took the top of the head pattern for a round head, and did it again for the bottom, but upside down.
Let me see if I can find that pattern here somewhere...
Take a look at this item...
http://puppetsandstuff.com/2008gallery/main.php?g2_view=core.DownloadItem&g2_itemId=11067&g2_GALLERYSID=184764bcf7c69a945ec4b9f8ffbb324fIt is from the puppetbuilding.com site, and was posted here in the past.
I checked on puppetbuilding.com and it is nowhere to be found that I could see.
It is a round head with a small bottom jaw, and if you play with it, you could take the round top, and invert it to use as a bottom jaw as well, I think.