This is a great image, and has a lot of neat ideas. I especially like the multiple faces, the weird jaw bone structure, and I probably don't even want to know what's in those sacs... I do think there should be slime on those tentacles.
This piece has single handedly turned Obox-ob from a cool demon lord that I'll use when I can to one of my favourites that has to be worked in whenever possible! This is an incredible digital painting that conveys otherness and insanity of an ancient lord perfectly.
I've always had a thing for the obyriths. That whole eldritch look that they all have and how they're just so horrifying their visage alone is enough to drive someone mad; my personal favorite obyrith lord is Pale Night, who I've done a picture of myself, but of the littler monsters, the ekolids, whom Obox-ob rules over, are the most preferable to me, and so I've had a bit of a thing for their prince as well. Great job, and I especially like how he's not as blurred here as he was in the official art. Excellent work, and while the colors are very definite, the way you'd applied them gives that slightly grayed, sickly look that any self-respecting obyrith would never be caught without. Awesome, awesome, awesome.