I’m not affiliated with them, but I believe they post anything they find and want to feature once they find on FA and Twitter. I wouldn’t say they’re stealing it though. They post the source and name of you as the artist. I don’t see how it’s different than if there was a NSFW furry art community on Lemmy and they posted a link to it there.
They do have a safe for work version of the site too, keep that in mind.
If you still want it removed, there’s a t link to a Do Not Post list at the bottom of the form so they don’t post any of your art. I’m sure they’ll remove it quickly
When I got my first one done, I got a simple reference sheet. I gave the artist a bunch of random images from Google, and the colors I picked out for my character. I would start with that, then branch out to other things like stickers, badge, or other artwork.