Hi all, I'm no master-painter and a less competent modeler, but I wanted to share my custom grots as other people's posts helped me immensely when I was trying to develop my army.
My core skin tone is Rakarth Flesh with airbrushed blue wash. I had decided that my haemonculus primarily made Grots out of captured Tau (with the exception of the demons). In retrospect, I wish I'd added some poison vials to the hell spawn.
40k Chaos Hell Spawn model with magnetized Talos arms; tentacles off the back are from a Cronos:
Warhammer Skaven Rat Ogre with flesh gauntlet right hand and close combat weapon left hand (from the Talos kit):
Warmachine Cryx Bloat Thrall with custom flesh gauntlet right hand and magnetized left hand. The flesh gauntlet is made from the top half of a Talos ichor injector and the bottom half of a Wrack scissor hand. (This model is relatively heavy as I had to fill in the body with magic resin after cutting off the Bloat Thrall’s gun):
40k Chaos Hell Spawn model with magnetized Talos arms: