Per Usual: Images and links are from Lexicanum or the Warhammer 40k wiki 

So due to my ennui and addiction to Satisfactory, I feel I did not do the Tau justice, well actually the Kroot, because they are one fucked up race.  So I am going to revisit the Kroot.

First – The Kroot

Humanoid in shape but are actually descended from an avian ancestor, the Kroot have hollow bones surrounded by very dense muscles with almost all of them being of the “fast twitch” type meaning they are very strong and very, very fast in their reactions and movement.  Instead of a left or right brain they have a frontal lobe and a rear lobe, with the front lobe being a lot larger than the rear lobe, the front lobe appears to be their center for logic, sensory analysis, and analytical thinking.  The rear lobe handles imagination and creativity, this is probably why the Kroot are a very pragmatic species.  The quills on their head are actually sensory in function giving them a lot of information about their environment, they have large nasal cavities, giving them an incredible sense of smell.  Their eyes don’t have pupils but allow them to see into the infra-red (I think of it as predator vision).  Because of all of this they make incredible scouts and trackers and in forested areas they actually move by jumping from tree to tree, making them hard to see.

The actually prefer to dress in animal hides and armor, eschewing manufactured goods for individuality and comfort.  This may also be due to the nasty smelling “sweat” they excrete which is also rather oily, there is a reason why the Kroot do not mix much with other races, well at least races that have the ability to smell.  This “sweat” is the waste products produced from what ever they have been eating and what function the “sweat” has is based on what they have been consuming, it can be heat-retardant to a degree, has antibiotic properties and can cause a poorly-aimed blow to slide clear.  It is theorized that they can also produce pheromones to leave trails, mark targets, leave warnings, as well as communicate.  The sweat also appears to have an effect on animals, calming them and keeping them from startling and giving away the Kroots position.  And do to their avian ancestors which were probably some sort of really ugly parrot, they can learn languages extremely fast, repeating the exact sound and structure till they understand the meaning.

All that is a bit strange, but is not what makes the Kroot all that interesting or fucked up, the next part is what I consider really interesting.  The Kroot have individuals known as Shapers, who are usually the leaders of the clans and the Shapers “shape” the Kroot by telling them what types of prey they can eat.  You want physically strong Kroot, go eat Orcs, you want Kroot with wings, eat a lot of creatures that can fly, you want smarter Kroot, eat humans or eldar.  One of the interesting things is that Kroot who eat intelligent prey start manifesting some of the prey’s cultural attributes.  Eat a lot of Dark Eldar and you have cunning and vicious Kroot who delight in murder and killing.  Basically somehow the Kroot instinctually know how to break down DNA and incorporate only those sequences which have the traits they desire.  Makes paternity tests pretty easy, just take a nip of someone and see if the DNA matches.  A Kroot Maury Povitch (You are not the father!) is possible or how about “Luke, I am your Father.”  “Noooooo”  “Here, just take a little nibble and taste for yourself!”

Sounds great and all, improving yourself through eating (at this point I would be Superman), but it does have a down side.  Eat too many dumb herbivores and you become a Trump supporter, eat too many dogs and you become a dog.  There are several animals that the Kroot use for labor or for war, such as the Kroot hound:

Kroot hounds at one point were Kroot, who through eating too much Chinese food became doglike Kroot hounds which are used for patrolling areas where they can detect even the most stealthy of opponents, guards for important Kroots, such as Shapers, and in battle where packs of Kroot can even bring down Space Marines.  They lost most of their intelligence but are on par with wolves.

Krootox –

Strong beasts used to carry heavy weapon equipped Kroot into battle.  Plus they can stand, and if enraged, most things piss them off due to just existing, they will lash out with their arms and rip enemies to shreds.  Can also be used as battering rams to destroy defensive lines and barricades.  They are basically bigger, meaner, and greener versions of Cape Buffalo.

Knarloc –

Raptor like mounts of the Kroot, fast in all senses of the word, with their forelimbs capable of shredding a foe like it was incriminating evidence, they are nasty in close up battle, but are mainly prized for their ability to carry a rider to battle.  Also a bit of a status symbol since only high ranked Kroot are able to procure one.

Now remember that all of these “beasts” are actually Kroot that have screwed up their evolution to become a new species, so having a Krootox would be like riding your distant cousin from Mississippi into battle.

And before you ask, yes some Kroot have become psychic by eating psykers and Eldar.  But the Grey Knights had their world destroyed by Exterminatus after having fought them, deciding they were way to dangerous to allow to exist.

So what can Kroot not eat?  Well, anything indigestible must be regurgitated in a very painful process, so nothing inorganic.  Also, the Tau are off the menu as they saved the Kroot race and if they eat any Tau, the Tau will hunt them down and kill them all.  They will not eat Tyranids (game respects game), they will not eat anything Chaos tainted because they may eat a lot of nasty stuff but they ain’t crazy, and of course Necrons.  Well they can eat the Necron living metal, but that experiment did not end well at all creating a plague of nano-scarabs that destroyed all life on the planet on which this particular buffet was held.