Take a look at Skaven stuff, they've got some truly gross monster bods and a bunch of mechanical bits and bobs to boot. Nothing specific comes to mind but that's a good place to start.
Also if you want to look outside GW, there's a warmachine faction (Cryx?) that's very haemonculaic and keeps drawing my eye for pain engine stuff.
Dark Angels. The Rock. Lion El "Dwayne" Jonson. I can't be the first person to have thought of this.