In 1977's Dragon Magazine #8, Gary Gygax published a one-page article informing players that there were alternate planes in the D&D setting, and giving a little bare-bones info about them. There were several supplements that expanded on that, and surely dozens if not hundreds of homebrew versions inspired by the idea, but it wasn't until 1987 that TSR published a comprehensive guide to the concept, the Manual of the Planes. The cover of the book featured a being called the Ethereal Dreadnought (today known as the Astral Dreadnought):
But wait. Computer, enhance!
Enhance and isolate!
Compress by 20% and hue shift down 20 degrees!
Mirror top right and bottom left of image!
In case you've forgotten, here's the original Doom Cacodemon sprite, at five times its original size:
And for one more fun experiment, what happens when you take the image we made before, turn up the saturation on the body, and desaturate the teeth and horns:
It even has the same heart shape on its forehead! But hey, if you've ever wondered what a "realistic" Cacodemon would look like, now you know.
There are TWO figures of the Astral Dreadnought now - both "minis." One really big one (I dunno, taller than a Marvel Legends, but taking up a ton of horizontal space with the tail) for like... $200. But also a smaller figure from a boxed set (like 3" tall, 5" long) that can be found at $35 or so.