Imperial Guard beastmen do in fact look like the ones from fantasy. Or did, back when they were part of the Imperial Guard.

-Which was First Ed. (aka 'Rogue Trader') only . The reference to 'beastmen' in the Abhuman fluff section of the most recent TT rulebook is referencing the White Dwarf article I quoted, which makes it clear that Chaos-style goat-headed beastmen are never tolerated in the Imperium; they have gone the way of half-Eldar Space Marines...

If I was playing with easily angered players, I'd be tempted to put a cat-person regiment into my OW game, just to annoy the people who take 40k too seriously.

Some people so easily forget that the Imperium is a really big place, and with a wide range of acceptable and unacceptable behaviours based on a laundry-list of issues. People have a tendency to over-interpret certain aspects of the overall setting, whether it's Commissars being able to shoot things willy-nilly, Inquisitors being able to lord over anyone and anything at any point, or the murder of accepted abhumans.

Insert a full regiment of felinids, the 81st Black Cats, a mobile, stealth-based hunter-killer regiment specializing in widescale application of night-time melee attacks. If you need images, look at the Star Wars Cathar.

Let's see, Felinids... Well, since everyone else seems more interested in fluff discussion, I'll change my usual tune and try to make some crunch.

Felinids are mentioned as having better reflexes than most humans (like Eldar Lite) and since most cat-people are recognized by their ears I'd give them bonuses to agility and perception, maybe a negative to fellowship since so many people feel RAEGE towards them. I'd make them suited to skirmishing, like light infantry.

I'm not used to making this stuff, so if I wanted to I might just take the Ratling specialty, change the minus to toughness into something else, and replace all the sniping abilities with things that help in melee.

Just shooting in the dark here, but I like Cat-peeps so I wanted to say something.

Maybe something like this?

Felinids are hot so lowering fellowship seems strange to me.

WS 25 +2d10

BS 15 +2d10

S 15 +2d10

T 20 +2d10

Ag 25 +2d10

Per 25 +2d10

Int 15 + 2d10

Wil 20 +2d10

Fel 20+2d10

It is strange, but that parts mostly meant as a joke about how many 40k fans hate furries. or, just how many people in general hate furries in anything.

Cat-person: Hey guys, I'm your new scout. Not only am I silent as a whisper and quicker than a snake, I've got super-cute ears that you will all want to pet me for just to touch them. For the Emperor!

Commissar: Private, she's getting fur all over my command tent. Bring my favorite Flamer gun, now!

*Bwoooooooosh!*

Now That was For the Emperor!

That's awesome 27th post before someone actually answered the poster's question!

It's funny how many people answer a question of what's the best way to do this with "YOU CAN'T!". Actually yeah you can, you can do anything you like in your game.

I think the posts above have the right idea, make the option a support specialist like ogryn and ratling (although I am sure there are other ways to do this too) start with the base stats and add extra bonuses and minuses based on your particular vision of how you think Felinids should be.

Add extra talents/traits that you think they should have in the same manner as ratlings and ogryns, perhaps unnatural agility (+2) and dark sight (or whatever it's called) and if you are making them really catlike you may want to give them unnatural weapons as well.

The more talents/traits you give them without any minuses should probably mean they receive less skills on their package.

Aptitudes should usually be 6 or 7 and again depends on your vision for how felinids should be.

As mutated humans? I'd just slap the appropriate mutations from WHFRP on them and call it a day. So, basic human with night vision, animal legs (+1 movement rate) and natural weapons. Done.

I know this post is a year old, but I just wanted to point out that Felinids could easily fit in as Gue'vesa regimets.

Given the xenophobic nature of the Imperium, its not hard to believe that some groups of Felinids might find their way to Tau controlled space trying to escape persecution, where they or their descendants could eventually wind up serving in the military if they so desired

I thought this topic would be about peculiar Tyranid fleet that spawns lefions of kitten to invade and devour whole planets.

I know this post is a year old, but I just wanted to point out that Felinids could easily fit in as Gue'vesa regimets.

Given the xenophobic nature of the Imperium, its not hard to believe that some groups of Felinids might find their way to Tau controlled space trying to escape persecution, where they or their descendants could eventually wind up serving in the military if they so desired

That's actually a pretty cool idea. Especially with the option to take the traitors regimental drawback. Many of the more accepted abhumans strains, like Ogryn and Ratling could even find themselves defecting considering the discrimination they deal with let alone lesser known abhuman strains and outright mutants.

I do have an interest in playing a game where players do play as a Gue'vesa regiment on a planet that fell to the Tau.

Made them part of my Abhuman supplement. You find them down amongst the new specialities.

https://www.dropbox.com/s/bd9wiamlywlxh0c/More%20Abhumans%20for%20Only%20War.pdf?dl=0

Feline Rogue Trader, anyone?

That still doesn't mean felinids are cat people, however. There's no reason to make them cat people unless you absolutely want to, and the cries of "furry, furry!" are your own fault, since you're the one who decided on that interpretation.

I'll go further: ultimately, whether it goes "NYAAA~ Catgirls" still depends on the fluff given to them.

So the felinids may well be made visibly catlike (Vaporians were said to have noticeably catlike features, yet still count as all human, right?), this just requires decent fluff that would make them more interesting than humans in cat suits - otherwise there's simply no reason to use them, other than said "nyaa".

With felinids what is "known" is exceedingly unclear (their planet is "isolated", but apparently they do get out and are not prevented from mucking around at all).

IMO this can be used to make them more interesting.

One of the interpretations may be that the tiger is tough, but steel bars are there to protect the tiger, rather than the other way around. Because in 40k the tiger is far from the toughest thing around.

Why would anyone bother? Perhaps because it's potentially valuable in some way.

Now we can for a hypothesis.

There are people in the Inquisition paying attention to this issue - who want felinids outside and specifically working for them, but also don't want everyone else to know something about the subspecies, which we may presume is not self-evident. But then, the Inquisition itself is limited in using felinids if they are too exotic and cannot walk around under a relatively innocent pretext.

So they pull strings in the Administratum to stop whatever contact there was under boring generic reasons, give Navy who would enforce the quarantine instructions as to what to watch for and what to ignore, and quietly inform the McConnell high-ups what should be kept under the wraps - and that they may go out to play, but step lightly. Then give a few Rogue Traders thought to be trustworthy dispensations to go ahead and hire felinids for dirtside teams - which works as "field testing", training the future officers of the Auxilia and preparation for starting new colonies - not even as much for the numbers, as for backup in case McConnell gets stomped by something.

The most obvious nasty secret being individuals with Warp senses (somewhere better than the Footfallen, but not as good or interactive as Navigators) appearing instead of Psykers (lack of psykers is common for abhumans, after all). Of course, if the Chaos guys hear about this, whether they think of it as "loot" or "liability", Carlos McConnell may have worse problems than merely being a Death World.

We can presume their world is a "mild" Death World, because (unless those who made them were "nyaa" type or something) a whole bunch of colonists are unlikely to be visibly modified for a boring paradise planet. As such, when the contact was established again, it could have become a hunting resort for those rich and tough or foolish - the foolish often refusing to hire local guides, with predictable results. Which may easily lead to some extra resentment and/or eventually also gives A.Administratum one more public excuse to close the planet when an Inquisitor requests a quarantine "until further notice".

«The ancient genetors wanted the colonists to actually own the place, not hide in caves or behind scorched ground or Iron Men, or anything like this. And this worked. They had skills far beyond what Mechanicus Biologis could do today, after all. But there often are… side effects. You have heard about those Afriel guys? Right. The thing is, cats were always used as familiars - both by the clean and unclean - and there's a good reason for this. You know how a cat sometimes hisses at something you can't see? It's not always merely a rat under the floor.»

Of course, if felinids appear in IG, the cat is out of the bag now.

Either there are a pair of colonies already or the timeline is rushed.

I propose to consider a Genestealer attempt at takeover of a convenient closed world - this can happen anywhere. Which the locals with Warp Sense are liable to notice and freak out over, begin the purge, discover that the full Genestealers are a bit too much even for people designed for a Death World, ask for assistance the first of "approved" Rogue Traders stopping by, the hunt for the infested Chartist ship, frantic Astropathic communications… a whole lot of mess.

And the next step of integration into the Imperium, including things like permanent Astropathic post on the surface and founding of local IG units and auxilia. Officially, "they have proven their ability and determination at fighting Xenos" now, unofficially it's both a good pretext to rush the next stage and a reminder why it's a good idea.

Feline Rogue Trader, anyone?

This would require someone to give one a Warrant. Now, having one in an entourage of RT, or better a whole band hired for exploration misadventures - would make perfect sense. "I did not want to hire them Kroot - they're trustworthy, but people get skittish next to something that clearly sees them as a potential next meal. Now, abhumans - why not, they can hunt well and it's not like anyone pretends a Navigator isn't on the ship."

Feline Rogue Trader, anyone?

I have a weird compulsion to now go and play Suikoden IV, though no Nay Kobold was this cool, I'm afraid.

Feline Rogue Trader, anyone?

This would require someone to give one a Warrant. Now, having one in an entourage of RT, or better a whole band hired for exploration misadventures - would make perfect sense. "I did not want to hire them Kroot - they're trustworthy, but people get skittish next to something that clearly sees them as a potential next meal. Now, abhumans - why not, they can hunt well and it's not like anyone pretends a Navigator isn't on the ship."

No, we just keep them confined to their ivory tower, for the good of us all; they can do whatever they do, away from "good" Imperials, and no one will get "accidentally" exposed to the third eye, or burn the only people who can get us back to what passes for civilization.

Also, perhaps give them more cat-like traits.

1. S and T bonus, but also some trait like Fatigues Easily (like Feliraptor in DH - "long" activity tests use T/2 rather than T) and/or something like " Short breath : when the character makes more than TB Strength-based tests in consecutive rounds (without skipping), must pass a T test (with modifier depending on S tests) or gain +1 Fatigue"?
2. Ambush Affinity: for purpose of XP cost may replace either aptitude with General for certain advancements: skills Acrobatics, Awareness, Stealth, Survival, and talents Ambidextrous, Berserk Charge, Catfall, Leap Up, Lightning Reflexes, Meditation, Resistance(Cold), Crippling Strike, Foresight, Furious Assault, Swift Attack, Preternatural Speed, Mastery(Acrobatics, Stealth); Ambush, Feat of Strength.
   Meditation ,
3. Feral Fallback : much like the Kroot and Space Wolves, Felinids tend to be affected by Corruption in one specific way: turning more and more into beasts.