Compare the entries and stats here to the “Lovecraftian Mythos” article in The Dragon. Despite J. Eric Holmes blowing off a reader’s suggestion to raise the hit points of the Great Old Ones, that’s exactly what’s happened—and a number of other criticisms have been addressed as well. My favorite part of the Azathoth entry—about the universe collapsing and all life being destroyed in the event of the creator’s death—has been removed, and instead of being “the creator of the universe,” Azathoth is now “the center of the universe.” The idea is to make the gods appropriately awesome and intimidating while also making them approachable from a role-playing perspective.
The illustrations are by Erol Otus, who, in my opinion, is the definitive early D&D artist and one of the greatest fantasy artists of all time. Lovecraft’s vibe suited him perfectly, and I wish he’d done—or would do—a portfolio or an illustrated edition. His smug Cthulhu is what I see when the name is invoked, and all the arcane denizens and their haunts shimmer with high strangeness and psychedelic mania.
To admire more Otus art from Deities & Demigods, visit The Erol Otus Shrine.
(Images via Dr. Theda’s Crypt)
2 Warps to Neptune 
While I had read Lovecraft prior to D & D – Otus’s artwork really solidified Lovecraft’s “monsters” in my heard when I was 12 or so…. Matt Staggs did a great interview w/ Erol Otus at Tor: http://www.tor.com/blogs/2009/04/an-interview-with-fantasy-artist-erol-otus