I thought of this guy while perusing the "Racism" thread. (For those who haven't read it, it's about non-human races and their interactions in RPGs, not necessarily racism as bigotry.)
I had mentioned that my current campaign world uses anthropomorphic animals as one of its non-human options. I wanted to have a variety of player races, since they're fun to play. At the same time, I didn't want standard fantasy tropes. Elves and Dwarves just wouldn't fit in this post-apocalyptic fantasy I had envisioned. Likewise, I didn't want to make up new races wholecloth, since that might be overwhelming to new players.
So talking animals it was. By designing them so that they had the exagerated characteristics attributed to their root stock, players would have a rough and ready guide to the race as a whole. Foxes are clever and tricky, dogs are loyal, cats are independent and so forth. Individuals vary of course, but it's along the same lines as saying elves are artistic, orcs are barbaric, Vulcans are logical, Klingons are honor-centric militarists, etc.
This is a long lead-in to this piece, but this particular one demonstrates something about the way I structure my illustration fees. In general, I have been told I charge too little for character illustrations. The reason why is several-fold.
First, I like doing them. They're fun. So I don't charge as much in the hopes that I'll get more commissions I enjoy doing.
Second, unless I work out details otherwise, I retain the rights of publication. A client can use the illustration for personal use and post it to websites with attribution. I charge slightly more to relinquish all rights. The reason behind this is that I can sometimes recoup the minor loss by re-selling the piece to another client.
Hence this piece. I had a humanoid rat on one of my campaign book pages. In an image search an emerging company called "Tarprat" found it. Now, they manufacture tarps for trucks, but for some reason, they wanted a warrior rat as their image. Being fine, upstanding folks, they didn't copy-paste-use on all their business material, but contacted me. I sold them the rights. This was an existing piece, but it still represented potential income.
Now i had a hole on my campaign page. So I made a new painting. Several years had passed by since the first illo, and I felt my painting chops had improved greatly, so it was a win-win for me. I sold the old one and painted a better one, which is below. The original for comparison is visible on their home page
in a slightly modified form.tl;dr: Here's a picture of a warrior rat.