The three-eyed Venus is largely the work of Avril Harrison, who did a bunch of the demo art found on copies of Deluxe Paint. Including that image, minus the third eye. I remember being amazed by it when I was a kid playing with my brand-new Amiga 1000. Note that it still carries her "A.H." signature.
I mean this is Warhol, King of Appropriation we're talking about here, so arguably it being on his discs suggests it is now a Warhol Original, but he didn't bother signing it with his name.
Harrison also did a bunch of other painterly stuff - the splash screen of the 16-bit versions of "Prince of Persia" is her work, she was part of the Monkey Island team, and various other appearances in the games of that era. Here's what I'm pretty sure is a partial gameography though I couldn't fill in the blanks if my life depended on it.
Also this article is reminding me that I have a few discs in a closet that I saved all my c64 art on that I really should get around to trying to extract someday before they bit rot away.