Alrighty; I sent Sep's comments to the artist, and asked him to start a new draft. I'll pay him for the sketch above (I am no oppressor of artists) since it fits my initial description quite well. Besides, Gihaahia is a shape-changer- perhaps this is her in a more feminine moment.
I should probably not be so hasty in commissioning pieces before I know what they are supposed to depict. If I had a short descriptive paragraph of a character in hand it would make it a lot easier for the artists.
I haven't seen the sketch for the evolved Mostin yet, but I did forward the old portrait by Doctor Midnight as a basis; it would be nice if an observer could recognize the two portraits as being of the same character at different times. I wanted Mogus to be more grotesque, Mostin to have a tentacle (I'm not sure what it will look like exactly- either a suckered tentacle or an oily pseudopod, most likely), and there to be more eyes on the robe. A different hat (artist's discretion), and a more animate beard.
I don't know if he will be a long-lasting antagonist, but I was thinking of Temenun (or one of the other 11) as a possible future commission. A thin rakshasa with the head of a white tiger. Is there more to Temenun than that?