Mr. Wilson
Explorer
Except you've got it backwards.
The Demogorgon of 1E had the baboon heads and tentacle arms. The notion of each head having its own personality, and vying with one another for superiority, is a much later addition. (Late 2E or 3E, I forget which.)
They gave the concept to the image, not the other way around.
Ah. I own up to that then.
I started playing DnD during the AD&D 2nd Ed days, so that's the only Demogorgon I know.
Props to whoever came up with the backstory to that portrait, that was inspired.