Well, there's been a bit of a break but I had enough cash left over from payday in order to order a model from
Eolith Miniatures: The Hurk model is designed to be a small model at 54mm scale, but at 27mm tall he'll fit perfectly amongst my INQ28 stuff, I reckon.
Here he is:

I'm going to be looking at him with an eye to converting him to better fit into 40k - which will probably entail a weapon swap or two... I liked the idea of including a minor race never really seen on the grand 40k battlefields. I did wonder whether to co-opt the Scythian race, perhaps most famous for killing the first Chapter Master of the Crimson Fists. They're apparently a race of warrior-monks that favour poisoned weapons. I did consider giving him some form of crossbow-type weapon, or a bizarre energy-based pistol.
As far as painting, I did get the image of some of these poisonous frogs:

Perhaps that'll help give an idea of where I'm thinking. I got a message back from Steve Buddle that Hurk comes in two pieces - the main body, and the shield. The shield is moulded to the hand and attaches at the wrist.