I wanted to get across what I visualized with Venkatesh's headdress so I decided to Google image search some pictures of "aztec priest".
This was one of the first images and it is pretty much exactly what I was looking for:
Each of those feathers would be replaced by a spine. Whether the skulls would be on the outside of the headdress or make up the head part of it is up for grabs. It would look suitably morbid either way.
Here is some jewelry and tattoos from Apocalypto, a movie I knew would have some inspirational material:
Again with a large headdress, although not as peacock as the first one. I figure Venkatesh would have some of that jewelry hanging from his neck and armbands and tattoos or multicolored scale patterns on his body.
Here is another big headdress:
Without even trying, I duplicated his skin coloration by choosing coral snakes as the temple servants.