I just started to sort out the different sketch titles/artists that have surfaced so far, and it is getting crazy. I already have seen 13 different ones, and I've counted four each already from Neil and Brent!
It's seems the artists are "cross-breeding" with this series. For example, I've seen both All Toads and Hairy Mane from Brent, and neither of those titles were his, either concept or art.