Mercenaries and pirates...

[InsaneInquisitor]

For the sake of interest and possibilities...

The Kroot are a Mercenary race that are willing to fight almost anything they consider worthy. Having said that, will it be beyond believe to have them in the employ of Dark Eldar Kabals? (I don't mean an individual, but rather an army so-to-speak).
On the one hand, them being mercenaries certainly would make sense, but on the other it would take quite an insane individual (or a really confident Corsiar Eldar/Craftworld Eldar) to actually join forces with someone prone to backstabbing you...

[Wildeybeast]

Most Kroot fight for the Tau, it's only a small minority who go out as mercenaries and they don't tell the Tau about it because it's obviously against the Greater Good. As far as I can tell, they don't really care who they fight for. I would think their only restriction is making sure they aren't going to come into contact with the Tau whilst acting as mercenaries.

[ElectricPaladin]

The Kroot are a Mercenary race that are willing to fight almost anything they consider worthy...

You kind of answered your own question here. The Kroot would only fight alongside the Dark Eldar if the price was extremely right, or they had reasons to believe the Dark Eldar would be forced to honor their word. The Kroot are canny survivalists. They don't get mixed up in situations they can't control.

[Nabterayl]

But beyond belief? No, certainly not. Remember that the kroot work as mercenaries so they can consume diverse genetic material, not so they can work for or fight against honorable warriors. If some shapers felt that working for a kabal would put them in conflict with (and thus in a position to eat) some rare or valuable DNA, and if they thought they could escape the Empire's notice, and if they thought they were sufficiently strong and/or otherwise able to resist depredation by their employers, yeah, they'd totally jump on that. Since dark eldar could get them on the other side of the galaxy potentially (something service to the Empire cannot do), I can see that happening.

[fuzzbuket]

some alliances will never work sadly

kroot+nids
kroot + crons
kroot + marines and stiff upper lip guard (think the volpone or mordians)

kroot+chaos deamons

but a clever kabal leader would happily employ kroot and then take the kroot and kroot hostages as prisoner ^_^

[MaltonNecromancer]

Ummm... given that in THE ACTUAL DARK ELDAR CODEX ITSELF it talks about how the Tau have had alliances with the Dark Eldar, why wouldn't the Kroot?

The thing everyone here seems to forget is that, yes, WE know the Dark Eldar are evil... but not everyone in the 40K universe does. Also, the DE are supposed to fit the "supervillain" archetype, even more than Chaos, and if there's one thing villains are good at, it's LYING. I mean, they run on things like deception and misdirection.

I reckon you could easily have factions of Kroot working for the DE for several reasons:

1.) It's just cool. 40K runs on stuff that either contradicts the fluff or doesn't make any sense, but it's in there anyway because it's cool. Ork teknology anyone? Makes not one lick of sense (they're all mildly psychic and the machines just work because the orks believe they will?!!), but it's one of the most awesome things in the game.
2.) The Tau themselves have worked with the DE, and the Kroot aren't anywhere near as advanced as them.
3.) Think of the conversion possibilities.
4.) The Wych Arenas have many, many alien creatures, all with delicious DNA just waiting to be gobbled up and assimilated. What self-respecting Kroot warrior wouldn't want to take advantage of that? Especially if s/he's a teenager and naive about "Being the greatest warrior in the galaxy".
5.) Vect. Are you seriously telling me he doesn't have some Kroot mercs somewhere that he's got just for giggles/to prove he can?

[The Sovereign]

Not only is it believable, it's actually probable. I submit the following evidence:

1. Chaos Marines employed Kroot mercs in a battle against loyalist forces in one of the Black Library books (forget which one). Most races in the galaxy consider Commorite/Craftworld Eldar as one and the same, and Eldar are preferable to Chaos. Therefore, Kroot have demonstrated that they'll work with almost anyone (barring Nids and Daemons).

2. It's more likely that Kroot will work with fellow xenos, even morally ambiguous xenos, before they'll work for xenophobic imperials.

3. Kroot Master Shapers are pragmatists. Dark Eldar haemonculi and archons are scheming pragmatists. Dark Eldar raid lots of planets with varied genetic material. Kroot require varied genetic material to evolve. Profit.

4. Dark Eldar love mercenaries (Sslyth anyone?).

So, not only is a Kroot/Dark Eldar alliance believable, it's extremely fluff adherent. Go for it. I did.

Note: As a bonus, GW produced a limited edition Kroot HQ so you can have a purely Kroot allied force. The character's name is Anghkor Prok. You can probably find his model on eBay, and if you Google his name you'll find a PDF of his White Dwarf rules.

[wittdooley]

Good looking out on Ankgor Prok. Hadn't heard of him before!!