GW Wracks

I've bought myself a set of the Finecast wracks and just wondered how other folks have painted them.

There seems to be a small blob of resin on the back of several of the models. I can't quite work out if it is supposed to be a tied up bunch of hair, or some kind of external vestigial brain. Any thoughts or experiences, I'd also appreciate anyone who can link me some photos of the back of a painted wrack because all the pics on the Gw site seem to be the same forward facing shot, no 360s for some reason.

The small blob is supposed to be there, there's no 360 shots of the studio ones but to me it looks like tied up hair in a Japanese style but you could paint it like anything.

I haven't painted my Wracks yet but I plan on doing them similar to the rest of my army, the armour will be coloured like everything else and the cloaks will be flayed skin.