Alex Grey - Transfiguration (help me understand it please!)

I have this on my bedroom wall and I love it, but there's some aspects of the image I don't quite get. Firstly in the lower half of the image there can be seen somewhat frightening or disturbing beings in the background in the darkness. They are not necessarily meant to be disturbing but the spikes and clustered eyes and tentacles make me believe they're meant to be so.

The other confusing element is the corruption in the man's left leg. Below the knee his leg is blackened, hairy, ape like (evolutionary ancestry?) But also seemingly infected with the evil creatures...

I was interested on what this meant to other Alex Grey fans?

 

cool artwork although i much prefer some of his other works