Well, having just "finished" an 1100 pt. Tau force for Warhammer 40K, I now find myself working on another Kroot army. Back in 2003-2004 I built and painted a Kroot Merc force. Now in 5th ed. 40K there are no official rules for this, but there is a nifty
fan-made codex that works well enough--as long as you're not fond of winning much!
Below is a shot of my old Kroot force, which I sold a while back to someone in the Pacific Northwest.

I had quite a bit more. My latest Kroot force is in its nascent stages, and will be started with the Carnivores from my Tau army:

Not sure where this will lead me. I may add some Great Gnarlocs from Forge World, or I may just focus on the stuff I can readily get at my FLGS: Kroot Carnivores, Hounds, and Krootox. I may run out of gas on this, but luckily this time I have a co-conspirator, Joe Urban of the
Sons of Blight blog. He's agreed to add some Kroot to the pot and combined forces with me. We can lose horribly together!
Scott