Jon Schindehette, a creative art director at Wizards of the Coast, issued a challenge to art students at the Rhode Island School of Design: Make creatures based on H.P. Lovecraft’s stories. These are just a handful of the awesome results. You can see more eldrich horrors on Schindehette’s blog ArtOrder.
Its body was eyes, mouths, and tentacles

This Shoggoth by Craig J Spearing is my absolute favorite. It’s about as close as a static portrayal can get to the shapeless, almost unimaginable aliens of the mythos.

Timo Karhula’s Dunwich Horror is great too. This one actually captures the formlessness of Lovecraft’s creatures best, but that very accuracy makes a less interesting picture just because it’s hard to tell what you are looking at. No fault to the artist, the whole idea of depicting the things that Lovecraft’s characters can’t even believe or understand when they are looking directly at them is flawed. The physics of the beings, by their nature, defy human understanding or depiction.

Will Martinez does an awesome deep one. This is great because it’s eerie and alien, yet conveys the truer horror that deep ones were humans.
The rest is good-but-typical fantasy horror monster art. Lovecraft is extremely difficult to redeploy in any medium but his own borderline-nonsensical prose. The horrors he reveals just don’t make sense, and wedging them into traditional forms of depiction, whether graphic art or film, are almost guaranteed to fail the Lovecraft purity standard. There are a few best-but-still-not-quite-right examples around, and these pictures are among them.
Hopefully del Toro’s At the Mountains of Madness will also be one.