This is exciting news. I love seeing your art. Even your color palettes are so amazing. I'm tempted to buy your deer if I could change their species to my deer/dog/bird type species. The blue, brown, and white all just go together so amazingly.
If you'd like to use the design to give a form of another species, you're free to it! I just recommend keeping the deer form as an "unofficial" form or something so the original design doesn't have to go to waste ;v;