Silicon carbide is a ceramic often used in vehicle and body armor, but could a living creature produce and use it the same way? Assume the creature was genetically engineered.
Plants make glass
Stinging nettle, ocean sponges and other plants produce glass. Nettles make their needles from it and sponges make their skeleton. These glasses made by plants are called "phytoliths", from the Greek "phytos", a "plant", and "lith", a "stone".
If silicon is already being used in lifeforms, the carbon and hydrogen is also already there so silicon carbide isn't out of the question.
This Nature article reports on electrochemcially producing silicon carbide in molten salt at 900°C. That's still pretty hot for the typical biological life form. Still, if the life form had an internal crucible made of silicon carbide, it is vaguely conceivable it could support a solution at 900°C.
This article from the U.S. Department of Energy Office of Scientific and Technical Information reports on room temperature electrochemical synthesis of a variety of carbide molecules, including SiC.
So just possibly an organism with a huge amount of available electrical energy, and some truly exotic chemistry, might be able to produce SiC. The exotic chemistry itself might be weaponized.
Maybe it starts with little nano-fibers that are glued together with more mundane forms of connective tissue. Then it gradually evolves to make larger and thicker plates. Possibly it can form claws out of the stuff. Possibly competition from similarly equipped creatures is what drives the improvements. Must have harder and stronger armor than George-across-the-forest or he gets all the girls.
One part of an organism that often contains some electrical energy is the nervous system. So, in effect, the critter might be able to make SiC armor by thinking about it really hard.
Intelligence and Knowledge are Weapons.
Silicon carbide is a ceramic often used in vehicle and body armor, but could a living creature produce and use it the same way?
Yes. They're called "hu-mans".
They may not be very attractive, but they're smart. What they lack in beautifully colored fur or feathers, they make up for by wearing sacks and painting themselves different colors. :-)
The fastest evolutionary path to developing sophisticated personal protection is intelligence. Nature will naturally tend to develop carbon-centered chemistry because it's what you're made of and it's relatively easy to work with. Everywhere in the universe carbon is going to be more abundant than silicon.
To evolve armor like that would take millions of years. Once you have intelligence (at a human social level) you can create more and more complex armor and out pace evolution by a factor of millions of times faster. That's the reason humans have stomped all over everything larger than a microbe ( still working on defeating the microbes :-) ).
It's no competition : you want well armored creatures, then you want smart tool making creatures that develop chemistry and alloys and ceramics and composite materials.
Assume the creature was genetically engineered.
Even more advantage in making them smart and flexible toolmakers.
If you want them to start out able to make such materials (or something similar) maybe you "hard-wire" the required skills and knowledge into them. At the very least you make them fast learners, concentrating your genetic engineering skills into giving them rapid comprehension and something like eidetic memory.
Let's say one faction engineering a silicon carbide growing creature. Well how long will it take the flexible intelligent toolmakers to figure out how to defeat that ? Engineer something with better armor, the smart tool makers will defeat that too.
I'll go with brains over brawn, thanks. :-)