My second Bloodthirster is based around the spare torso that comes in the Bloodthirster box, plus a raid on my bits collection. You get 2 torsoes in the box because one head has an attached neck and the other doesn't. A nice bonus, I thought!
The legs are the back legs of a Forgefiend/Maulerfiend, they have that goaty feel that's oh so Khornate. Plus lots of pistons, helping anchor the model in 40k. They were joined by a plastruct tube, and then I filled it all in and bulked it out with green stuff.
The head is from a defiler, and the wings are from a daemon prince. The lower arms are also from a daemon prince - the whip/tentacle arm is meant to be his tail.
He just needs a chain going up his rear - I've got to dig around deep in my craft box, but I'm sure I remember seeing one in there.
And now one final shot, of the family so far. This guy is a bit less tall than the official Bloodthirster, due to the wings, but he's got a bulkier lower body and I don't think it's game-breaking. Next I need to work on both their bases, and then break out the paint!