# How could you make a cat's tail prehensile enough to use weapons?

Simply for the cool factor I wanted to have my humanoid cat person tri-wield: one sword in each hand and a third in their tail. But would it be scientifically possible for the cat-person to have enough control over the tail to hold a blade (or possibly other weapon) and use it effectively enough for it to be worth it (otherwise naturally the cat-person will just use their tail to fight in other ways)? Ignoring of course the mechanics of dual-wielding itself; I simply want to know how, if at all possible, a cat's tail could be made able to hold a weapon without magic (see below).

I could simply ask 'a wizard' to do it with magic because this is a fantasy setting, but it seems much less... cool. Plus I'm interested in the science basis of a prehensile tail.

• – Sec SE - clear Monica's name Jul 30 '17 at 10:00
• What kinds of muscles and joints and so on does your tail have? You can always make it similar to an arm, thus giving it enough control. I think most animals have really small muscles controlling their tails, so it wouldn't be viable, but since this is make-believe, you can make it viable. If you ask it like this though, the question that one has to ask if dual-wielding is ever worth it. You can have two different kinds of "weapons" serving different purposes or just for show/sports, but 2 equal weapons is already pretty suboptimal. I think a heavy/long weapon supported by the tail ... – Raditz_35 Jul 30 '17 at 10:27
• ... would be better for example. But that also depends on formations, battle tactics and so on. Please also consider that a tail would be a massive weakness since it's such an easy target. If I were a cat person outside a phalanx or something, I'd feel more relaxed if it was under some armor, certainly not facing the enemy. Also, and this is just my opinion, I hope such a statement is ok since I already wrote a lot, you cannot possible make a humanoid cat person cool ;) – Raditz_35 Jul 30 '17 at 10:29
• I made some edits in an attempt to obtain some more specific answers. – C. R. Yasuo Jul 30 '17 at 10:38
• If you only want cool, you might have a small, light weapon meant to be attached to the tail - a spike or blade, a weight for clubbing with, sharp ridges, etc. It wouldn't have much force behind it, probably not enough for serious injury, but it may be able to basically serve as a distraction when thwapped with. Some extra flexibility or control may help the person use it to target soft spots, or serve as an unexpected threat when hands are otherwise busy. And it could be made to look quite impressive - shiny, spiked, or rough - depending on the character's aesthetics. – Megha Aug 1 '17 at 4:10

As a general rule, $flexibility \propto {1 \over strength}$.

In other words, your cat's tail will have to be muscular enough to bear the weight of the sword and the weight of the tail itself for every possible angle at which it can bend. At the same time, it needs to be flexible enough to wrap tightly round the handle of the sword.

You can't have both. In order to be sufficiently muscular, the tail would be so thick that it couldn't wrap round the sword, while a tail thin enough to wrap round a sword couldn't support its weight. Think of the tightness of a knot on a ship's hawser versus a piece of string. Limbs can manage it because of the long bones that allow a long length of muscle to distribute the load over, plus the bones that actually act as a stiff framework for the muscles to regulate.

In effect, a cat wielding a sword with its tail is far more likely to cut off its own legs than hurt an enemy.

I think adding woolly monkey genes would probably be the best starting point. Of course the pelvis section would have to be strengthened to give a solid base. Frankly I think the 'humanoid' cat person meme is oversold. Cats are fine shaped the way they are. Two additions might be polydactyl paws to give an opposable thumb and some genes from an otter. The muscular tail could be used as a powerful swimming device. On land the tail could be used for heavy work while the paws and fangs would be used for fine tool making. Imagine a 'hypercat' hanging from a branch over a brook waiting with catlike senses waiting for a tasty fish to drop onto. Or chasing birds and squirrels through the trees with its tail and opposible thumbs augmenting its swings through the green canopy.

Genetic engineering could take the specific genes from a wooly monkey, or one of the spider monkeys, and insert it into the cat genome to produce a cat with a prehensile tail. Such a cat could grasp light objects (only) in its tail; or enable the cat to hang by its tail from a tree or a chandelier.

If the existence of a humanoid cat person with the ability to use tools is plausible, it seems equally plausible for that cat person to have a prehensile tail with similar properties to a simple hand that could also be used with some tools.