Synthetic animal with super skin: Looking for Biotic material that's Elastic, hard to cut and puncture with force

Question

Hey first post here!!

I have a species of Synth-animal that is designed to upset ecosystems, consume all crops and livestock, and depopulate cities. The animal is around the size of an American black-bear but they act like omnivorous locusts swarms when in large numbers (they don't fly to be clear), eating everything in their path. They are similar to Combine-Synths in the Half-life series. A big difference is they are observed growing and are able to reproduce on their own.

The Current issue

Although most of their upper body is coated in dense bony scutes, the animal's underside and the exposed gaps between this plating is vulnerable. Also, similar to the honey-pot ant, they have special workers called "repletes" that act as food storage tanks. It's slow moving and very vulnerable in this "storing" state. So that skin is going to be both stretchy and sturdy enough to take a beating. This synth species is designed with humans in mind, so its engineers made them to survive a good bit of what we could dish out at it.

A few clear parameters :

• Humans want to kill these things, I'm not looking to make them bulletproof, just strong enough to where a serrated knife would not be able to cut open their exposed skin, it should be arrow resistant and a stab won't puncture it, or at the very least it's going to take some time and serious applied force to do some damage.

• Blunt force should not cause the skin to split, though bruising it is fine. For instance, a strike from a strong human with a baseball bat or a mallet to it might bruise it but it won't be enough to split the skin.

• The skin can be made of something that isn't usually found in nature but must be something that an organism could produce.

• This material must be very elastic and be able to return back to its original form without compromising a lot of its durability.

• For the repletes this material has to be able to -while stretched- hold between 100 to 400 pounds of organic paste (not directly of course, there's an organ to do that but I guess that organ would be made out of a similar material.). Not sure how many times larger it needs to stretch, lets just say it needs to expand to store at between 12-50 gallons of extra fluid.

Thanks for any input!! Hopefully this is descriptive enough!!

Answer 1

Spider Silk

When it comes to resisting tearing, you can't do much better than spider silk. Stronger than steel, more resilient than Kevlar, and able to stretch up to 10 times its original size and snap back into shape, you pretty much need ultra-modern tech to surpass it in unbreakability, and the only reason why it isn't widely used in military armor is because it is so expensive to produce (spiders eat each other if kept together and it's difficult to harvest their silk automatically). There have been advances made by genetically engineering goats to excrete the proteins in their milk, but it isn't as strong as the real thing, which must be spun into threads as it solidifies.

A creature with spider silk or a similar protein naturally incorporated into its skin would actually be bulletproof. The one thing holding it back is that while it is extremely strong, it is also very stretchy, so by itself the skin might have a hard time protecting the internal organs from blunt trauma unless it was also very thick. However, if your objective is to make a nigh-unbreakable storage sack, it's hard to find something better.

Answer 2

Honey Badger Skin

Honey badgers are notoriously hard to kill, and one reason is their skin. It's thick and tough as anything, but also it's sort of folded or furrowed and only loosely attached to the flesh underneath, which means that it tends to move and unfurrow/effectively stretch when something tries to puncture it. It allows the honey badger to squirm, turn, exercise its bad attitude and savage whatever is attacking it.

Add some very small, hard carapace scales for additional protection if you like, or stick a fibre mat under it.