Flight Rising, a browser-based game that revolves around breeding and collecting dragons, occasionally hosts contests for "Skins and Accents" that can be used to change the appearance of a players dragon, restricted by existing line-art, shadows, and artistic stylings. The entries above were all winners in a "Coliseum Challenge" and are based on enemies that can be fought in game.

You can find them in game under the names "Molten Wartoad," "Paradise Zalis" and "Nightmare."

You can visit Flight Rising here: https://www1.flightrising.com/