Kandra and limb count

[DoctaDajman]

I will have to @Trusk'our on this one as it is a question directly related to kandra. 

How many limbs do you think a single kandra can operate effectively at once?  

I know that the limiting factor here is a lack of skeleton but lets just pretend for a moment that this kandra can grow the required structure to allow these limbs to function.

We know that Kandra can't take the form of anything too large, but how much does their mental ability to control the limbs strain?  

4 arms is better than 2 but my mind has an insanely difficult time trying to imagine operating 4 arms and not getting tangled up. 

 

[Treamayne]

2 hours ago, DoctaDajman said:

I will have to @Trusk'our on this one as it is a question directly related to kandra. 

How many limbs do you think a single kandra can operate effectively at once?  

I know that the limiting factor here is a lack of skeleton but lets just pretend for a moment that this kandra can grow the required structure to allow these limbs to function.

We know that Kandra can't take the form of anything too large, but how much does their mental ability to control the limbs strain?  

4 arms is better than 2 but my mind has an insanely difficult time trying to imagine operating 4 arms and not getting tangled up. 

Kandra do not have a centralized nervous system or a single "brain" (at least not like a human's):

Spoiler

zas678

TenSoon wonders, and I wonder too- How can kandra think and be sentient without brains? Doesn't the body need a physical coordinator to relay between the Physical and Cognitive realm? Or do the spikes do a good enough job with that?

Brandon Sanderson

I imagine kandra having a non-centralized nervous system, with brain power spread through their bodies. Well, non-centralized is probably the wrong way to say it. They have lobes of thought and memory attached to muscles here and there, and don't have a single 'brain.' They certainly have brain-like material, though.

/r/Fantasy_Bookclub Alloy of Law Q&A (Jan. 17, 2012)

As long as they have a skeleton for it, the muscles controlling the limb would have the lobes for controlling that limb and interfacing with the rest of the body, so size and skeleton is the limiting factor, not limb-count. Granted, like other senses and such, if they are not "learning" about a body by consuming one, then trying to self-teach a 6 limb+ structure using a "true body" would be very difficult. As TenSoon shows in HoA - get enough practice with a biological component, and the Kandra can improvise and adapt those structures without needing a "template."

Dragonsteel/Yumi Spoilers:

Spoiler

There are already four-limbed sapient beings in the Cosmere - the Sho-Del (cameo only in Yumi). The hold the same ecological niche as Humans in the Fain Ecosystem. 

 

[DoctaDajman]

3 minutes ago, Treamayne said:

Kandra do not have a centralized nervous system or a single "brain" (at least not like a human's):

  Hide contents

zas678

TenSoon wonders, and I wonder too- How can kandra think and be sentient without brains? Doesn't the body need a physical coordinator to relay between the Physical and Cognitive realm? Or do the spikes do a good enough job with that?

Brandon Sanderson

I imagine kandra having a non-centralized nervous system, with brain power spread through their bodies. Well, non-centralized is probably the wrong way to say it. They have lobes of thought and memory attached to muscles here and there, and don't have a single 'brain.' They certainly have brain-like material, though.

/r/Fantasy_Bookclub Alloy of Law Q&A (Jan. 17, 2012)

As long as they have a skeleton for it, the muscles controlling the limb would have the lobes for controlling that limb and interfacing with the rest of the body, so size and skeleton is the limiting factor, not limb-count. Granted, like other senses and such, if they are not "learning" about a body by consuming one, then trying to self-teach a 6 limb+ structure using a "true body" would be very difficult. As TenSoon shows in HoA - get enough practice with a biological component, and the Kandra can improvise and adapt those structures without needing a "template."

Dragonsteel/Yumi Spoilers:

  Hide contents

There are already four-limbed sapient beings in the Cosmere - the Sho-Del (cameo only in Yumi). The hold the same ecological niche as Humans in the Fain Ecosystem. 

 

Fascinating. And I suppose a Kandra who understands the anatomy of an animal would be able to ramp up that size or shrink it down assuming they have a true body that will allow it as well? 

 

[Treamayne]

39 minutes ago, DoctaDajman said:

Fascinating. And I suppose a Kandra who understands the anatomy of an animal would be able to ramp up that size or shrink it down assuming they have a true body that will allow it as well? 

That is the implication from Tensoon in HoA Ch 66 when he ate a horse and a pig to make a horse with more muscle mass and density for moving through the ash:

Spoiler

TenSoon considered this concern, then had ordered a horse and a large hog to be brought to him. TenSoon first ingested the hog to give himself extra mass, then molded his gel-like flesh around the horse to digest it as well. Within an hour, he’d formed his body into a replica of the horse—but one with enhanced muscles and weight, creating the enormous, extra-strong marvel which Sazed now rode.

So, in theory, if a Kandra knew a life-form well enough to create it's muscles and organs without a template (see HoA Ch 7) then with an appropriate amount of mass and a true body skeleton to match that mass, they should be able to form a functional body of that size. 

Found the reference - HoA Ch 9 has a four-armed Kandra cameo:

Spoiler

She had a new True Body—an eccentric one, with bones made of wood. They were thin and willowy in an exaggerated, unnatural way: her wooden skull long with a pointed triangular chin, her eyes too large, twisted bits of cloth sticking from her head like hair. The younger generations were pushing the boundaries of propriety, annoying the Seconds. Once, TenSoon would probably have agreed with them—even now, he was something of a traditionalist. Yet, this day, her rebellious body simply made him smile.

That seemed to give her comfort, and she found a seat, near the front, with a group of other Seventh Generationers. They all had deformed True Bodies—one too much like a block, another actually sporting four arms.

 

Edited February 3, 2025 by Treamayne
SPAG/Ref:

[DoctaDajman]

20 minutes ago, Treamayne said:

That is the implication from Tensoon in HoA Ch 66 when he ate a horse and a pig to make a horse with more muscle mass and density for moving through the ash:

  Reveal hidden contents

TenSoon considered this concern, then had ordered a horse and a large hog to be brought to him. TenSoon first ingested the hog to give himself extra mass, then molded his gel-like flesh around the horse to digest it as well. Within an hour, he’d formed his body into a replica of the horse—but one with enhanced muscles and weight, creating the enormous, extra-strong marvel which Sazed now rode.

So, in theory, if a Kandra knew a life-form well enough to create it's muscles and organs without a template (see HoA Ch 7) then with an appropriate amount of mass and a true body skeleton to match that mass, they should be able to form a functional body of that size. 

I know it's corny but studying a jumping spider and replicating that on scale would be terrifying. I assume teeth fangs and claws are in the same boat as hair and bone. But for a kandra who had access to someone.. or something that could create an exoskeleton for them they could replicate far faster travel than just a beefy horse. 

[Treamayne]

9 minutes ago, DoctaDajman said:

I know it's corny but studying a jumping spider and replicating that on scale would be terrifying. I assume teeth fangs and claws are in the same boat as hair and bone. But for a kandra who had access to someone.. or something that could create an exoskeleton for them they could replicate far faster travel than just a beefy horse. 

Perhaps that's part of why there is a Kandra on Roshar - learning to inhabit exoskeletons instead of wearing endoskeletons, and using multi-limbed forms. 

WoBs:

Spoiler

Quote

R'Shara

Did the kandra that's running around on Roshar have a speaking role in Oathbringer?

Brandon Sanderson

RAFO!

Skyward Pre-Release AMA (Oct. 19, 2018)

Quote

Pagerunner

The kandra on Roshar. Is that Felt's wife, Malli?

Brandon Sanderson

RAFO! That is an excellent question that one should indeed be... yeah.

JordanCon 2021 (July 16, 2021)

Quote

Ok-Row1050

If a kandra with a crystal True Body made their way to Roshar, could they use their crystal bones like a gemheart?

Brandon Sanderson

Yes, they could. That is an excellent question.

YouTube Spoiler Stream 4 (June 16, 2022)

Quote

Nextorl

In The Lost Metal, MeLaan is said to be the first kandra Harmony sent off-world. Does that mean that the kandra on Roshar are not in Harmony's employment?

Brandon Sanderson

Yes! Good way to connect the dots. That is exactly what that means.

R'Shara

Brandon, you previously said the kandra on Roshar WAS an agent of Harmony.

Brandon Sanderson

Did I? *sounds uncertain* Well... I'm changing my mind. Yeah. No. I... uhh... Nope, not an agent of-

I know exactly who this kandra is and what they're doing and yeah. I'm going to say I don't know why I said that before, but now, no.

Footnote: R'Shara is referring to this WOB where Brandon says that the kandra is an agent of Sazed
YouTube Spoiler Stream 5 (Dec. 2, 2022)

 

 

Edited February 3, 2025 by Treamayne
SPAG

[Quantus he/him]

2 hours ago, Treamayne said:

Perhaps that's part of why there is a Kandra on Roshar - learning to inhabit exoskeletons instead of wearing endoskeletons, and using multi-limbed forms. 

WoBs:

  Hide contents

 

 

If exoskeletons are not a barrier (or at least one that's surmountable) then theoretically they should be able to mimic any of the multi-limbed crustacean species on roshar up to whatever their normal size limits might be, at least until some form of spren bond become required (for sheer weight, etc). 

Edited February 3, 2025 by Quantus
Awful spelling...

[DoctaDajman]

12 minutes ago, Quantus said:

If exoskeletons are not a barrier (or at least one that's overcomer) then theoretically they should be able to mimic any of the multi-limbed crustacean species on roshar up to whatever their normal size limits might be, at least until some form of spren bond become required (for sheer weight, etc). 

I imagine that a blessing of potency would actually really help here as well. I can't really say whether an exoskeleton is that much heavier than a typical skeleton but certainly a blessing of potency kandra could carry around a thicker one and do more with it. 

[Trusk'our he/him]

On 2/3/2025 at 10:06 AM, DoctaDajman said:

I will have to @Trusk'our on this one as it is a question directly related to kandra. 

How many limbs do you think a single kandra can operate effectively at once?  

I know that the limiting factor here is a lack of skeleton but lets just pretend for a moment that this kandra can grow the required structure to allow these limbs to function.

We know that Kandra can't take the form of anything too large, but how much does their mental ability to control the limbs strain?  

4 arms is better than 2 but my mind has an insanely difficult time trying to imagine operating 4 arms and not getting tangled up. 

As @Treamayne has brought up, there is at least one example of a Kandra with four arms. Though we don't see them used I find it hard to imagine the Kandra keeping that form if it were truly unwieldy.

I think, then, as long as a true body were sculpted with the correct structure they could coordinate a large number of arms- especially given that their brain mass should be flexible. Larger bodies IRL require more neurons to control (which is why some creatures like whales and elephants have bigger brains than humans despite having less sapience), so a Kandra with added arms should be able to coordinate with a some practice so long as they add some brain lobes along with the extra limbs. This is also supported by Kandra greatly increase their mass without losing coordination, like when TenSoon becomes a bulky horse or even just with Mistwraiths' typical body plan.

Added arms would increase total weight, but I doubt it'd be enough to seriously disrupt their total capacity.

There's also some issue regarding how the muscles and bones would be placed- I don't think an actual human body plan could do it without serious modification. I think if a Kandra tried to take a human skeleton and plaster on an extra pair of arms they'd have to become pretty grotesque in their upper body to support them, and the rotation of the secondary arms may still be more limited that the original. 

But, I'm no biologist, so perhaps these worries aren't as founded as I make them out to be. Whatever the case, I'm sure a Kandra could make four arms work with some effort (though any more will probably involve becoming a centipede by necessity).

[Duxredux he/him]

I think the best indicator for how much control the kandra can have over their muscular system is TenSoon reclaiming the wolf hound body. It was presumably with his morphing muscles that he was able to sort through and place all of the fur into their proper pores on the fly. Being able to sift through individual hairs, identify each one, and put them in place as an afterthought makes moving like a centipede look simple. I expect Kandra will be able to mimic any animal of a similar scale, barring any materials or Invested abilities they can't replicate.

That said, some mechanisms simply don't scale up due to the square cube law. A kandra-sized jumping spider will not be able to make the same proportionate leaps as their tiny counterparts because their mass increases by a higher factor than the cross section of the skeletal and muscular systems.

Extra limbs also may not be as useful as you might expect. For example, think of the kinesthetics of throwing a proper punch. To get maximum power, the arm is not the only thing in motion, but the torso, back, hips, and legs all twist to add force to the strike. Adding multiple limbs to the strike adds a little bit of mass, but divides the force between the contact surfaces. More limbs for transport adds stability (useful for crustaceans in a tidepool, the IRL inspiration for Roshar), but presumably requires more energy to move in concert than a creature with fewer limbs. Humans as bipeds are among the top in terrestrial endurance animals on the planet with some native groups like the Rarámuri who hunt by running after prey animals until the target dies of exhaustion.

Okay, maybe adding more arms and eyes may help when fire arms become prevalent, but I didn't notice particularly good reaction times from MeLaan or VenDell who were repeatedly surprised at how fast Wax reacted in a fire fight. Adding eyes and limbs is only useful if they can be used with accuracy. Admittedly there are also technical tasks when I wished I had a third hand and had to improvise with tools, teeth, or feet.

What Kandra can do that others can't is swap between modes - so long as they are willing to pay the cost for carrying or placing the skeletal structures to accommodate the needed swaps. Considering how decidedly unstealthy MeLaan was lugging her sack of skeletons around in BoM, this is not trivial.

What I would fascinating is a Roseite Aetherbound Kandra who could modify their skeletal structure on the fly. Wonder if we'll see one.

[QuantumAce]

On 2/3/2025 at 12:27 PM, Treamayne said:

Perhaps that's part of why there is a Kandra on Roshar - learning to inhabit exoskeletons instead of wearing endoskeletons, and using multi-limbed forms

Kandra plus Sleepless could be...interesting.

Both should be capable of far more creative or specialized bodies than we have seen so far, but both require more practice the farther they get from their most commonly used configuration. 

[DoctaDajman]

15 hours ago, Duxredux said:

What I would fascinating is a Roseite Aetherbound Kandra who could modify their skeletal structure on the fly. Wonder if we'll see one.

This 100%.  The real motivation behind my questions... 

I like your examples of why extra limbs may not be the answer. The biomechanics make sense. 

So who makes the better in world character trying to replicate the iron spider / doc ock arms, a kandra who will have direct control over their extra limbs or an awakener with awakened ones?  Or is there simply a third group that is aetherbound who grow the extra limbs and use them via their aetherbinding? 

Edited February 6, 2025 by DoctaDajman

[+robardin he/him]

How much mass would the kandra on Roshar have to eat to be able to take on the form of a chasmfiend?

And, what can a kandra do to disgorge excess mass, so to speak? If TenSoon ate a horse and a pig to be able to form a (larger) horse, which would be upwards of 1500 or even 2000 lbs., wouldn't that affect his ability to mimic a human again unless he dropped mass?

 

Maybe it's best not to get into too much detail on what that would look like, but the primary thing I'd be wondering is, would it have to look like mistwraith "protoplasm" (severed mass) or could the kandra form the mass while releasing it, to resemble something inocuous ("wow, where'd all these dead rats come from in this alleyway?")

[Treamayne]

4 hours ago, robardin said:

How much mass would the kandra on Roshar have to eat to be able to take on the form of a chasmfiend?

Enough to die by Square Cube Law. WoBs:

Spoiler

Quote

Questioner

What are the upper limits size-wise of what a kandra form can take? Could they say eat a chasmfiend?

Brandon Sanderson

Well, they would have trouble with the square-cube law, and a chasmfiend does not, because they have a symbiosis with natural spren, which keep them from crushing themselves. *scattered laughter* So a kandra would crush themselves if they tried to do that.

JordanCon 2016 (April 23, 2016)

Quote

Questioner

What are the upper limits size-wise of what a kandra form can take? Could they say eat a chasmfiend?

Brandon Sanderson

Well, they would have trouble with the square-cube law, and a chasmfiend does not, because they have a symbiosis with natural spren, which keep them from crushing themselves. *scattered laughter* So a kandra would crush themselves if they tried to do that.

JordanCon 2016 (April 23, 2016)

Quote

Jason

Can kandra absorb living matter, non-organic matter?

Brandon Sanderson

They do absorb living matter, but it’s more what can they eat. So, chasmfiend carapaces, they probably couldn’t digest.

Figment chat (Jan. 19, 2015)

Quote

Cadmium (Written) (paraphrased)

Would it actually be possible for a kandra to "become a rusting bunny?".

Brandon Sanderson (Written) (paraphrased)

Yes, But it would be tough.

Brandon Sanderson (paraphrased)

They must keep a certain mass to maintain intelligence and a bunny is very small.

Cadmium (paraphrased)

But obviously being a Harvey sized bunny is totally doable.

Brandon Sanderson (paraphrased)

Yeah... Good movie reference. Calamity Houston signing (Feb. 24, 2016)

 

 

4 hours ago, robardin said:

wouldn't that affect his ability to mimic a human again unless he dropped mass?

My guess is that Kandra don't drop mass as shed limbs/objects, rather there seems to be a distinct difference between digesting mass (as food) and eating masss to incorporate into their form. TenSoon as OreSeur as Wolfhound ate regularly (asking for aged meat when possible) and never grew any larger. For that matter, TenSoon comsumed OreSeur and didn't become a double-sized human before consuming the first wolfhound. It seems that consuming bodies to increase mass is a possible process, but not the norm. 

Likely they can digest extra mass as food over time (TenSoon was back to Wolfhound size in SoS) to reduce mass.

Edit: Correction - they can expel excess mass - MeLaan implies it expels like a liquid (or th liquify it to expel it) - SoS Ch 17:

Spoiler

“In answer to your question,” MeLaan said, “it is hard, but not for the reason you’re implying. We can force-feed and expel excess, which makes doing the transformation near a drain like in here convenient. The tough part is memorizing the muscle patterns as you digest them. That and getting the hair right. You people are practically drowning in the stuff. Fortunately, for a quick change like this, I can ignore the hair under the clothing.”

 

Hope that helps

Edited February 10, 2025 by Treamayne
SPAG/Ref.

[AltonicKeys he/him]

So, about limbs... Can kandra use their organic matter however they want, or do they have to form the shape of whatever they ate?

For example, could a kandra take 20 human femurs and become a 20-point star and move around like a sea urchin? Could they take 60 femurs, and become a 20-point star, each limb with 3 bones, 3 points of articulation, like a finger?

[Duxredux he/him]

1 hour ago, AltonicKeys said:

So, about limbs... Can kandra use their organic matter however they want, or do they have to form the shape of whatever they ate?

For example, could a kandra take 20 human femurs and become a 20-point star and move around like a sea urchin? Could they take 60 femurs, and become a 20-point star, each limb with 3 bones, 3 points of articulation, like a finger?

They have a huge amount of flexibility and can reroute on command. MeLaan for example opted to store her memories in her thigh while her head only held sensory apparatus and an emergency canteen. MeLaan was able to reroute the human digestive tract sufficiently to let her belch from a mouth formed on her hand, presumably with all of the complications transferring the gas out to a limb would entail. She later used this setup when performing surgery on Marasi, taking a bite to let her replicate Marasi's tissue, suck out any of the bile spilled from the gut wound and expel it, before suturing her closed with tissues she already had ready. Soft tissue manipulation for Kandra is pretty standard.

As for the sea urchin question, a mad hodgepodge of skeletons of various animals moving along is basically the default for Mistwraiths. Whether or not the specific bones articulate well or are suited for the mode of transportation are a separate issue but mix, match, and make do is the default. What Kandra do with mimicry and designed advantage is harder.

Edited February 10, 2025 by Duxredux