Bits

One of the Materials used for crafting and trading.

After killing a creature you can, unless it’s been annihilated, usually harvest some bits. Bits are a generalization of organs, glands, bones, and other valuables. Your character would intuitively know what parts of a creature are valuable, even if you don’t yet.

Basic Bits

Simple unimpressive creature viscera, not useful for much more than cooking or filler.

Blood, mundane organs, bones

Artisan Bits

Purposeful materials from creatures with clearly developed biological systems doing useful things.

An undead creature’s ichor, the claws of a powerful predator, eyes of a creature that can see in the dark

Exotic Bits

Similarly highly developed biological systems, but doing truly incredible things.

The regenerating heart of a golem, the blood of an elder vampire, the fire spewing lungs of a dragon.