Got this from trying to see if it can make two or three stage fakemon lines for funsies. And this was my attempt, without giving it any extra info on what to do.
"a three stage fire type starter pokemon based off a bison, growing bigger in form and power each stage, cel shading, Pokemon style, in-game screenshot, HUD, 3d" was the prompt. Just change the typing and the species/ect. and add details you want, and then ez fakemons forever.