Items & Creatures
Animals, monsters, items and other thing that can be summarized as "things that exist within the world (but aren't characters, geopgraphy, religion, etc."
If it's something you can interact with, it probably should be listed here.

Monsters
Unfriendly creatures

Caustic Bronco
The Caustic Bronco was a dangerous but valuable creature found in the Southern Desert. Like a horse crossed with a rattlesnake, it is unknown whether these creatures developed naturally or as the result of some arcane experiment. Either way, the result is a wild and ill-tempered creature that gallops quickly and bites with paralyzing venom. If one can manage to tame a Caustic Bronco, they will have a fearsome mount from which to terrorize open terrain. Some of these trained beasts can even be taught to spit their venom a short distance.

Animals & Beasts
Non-hostile (by default) creatures

Auroch
Auroch were massive wild cows, with bulls standing 2 meters tall and cows standing 1.8 meters. They had large, wide horns, and travelled in large herds in the Northern Tundra. They had an ornery temperament, but a nomadic tribe capable of felling one of the beasts would be fed and clothed for a long while.

Items
Objects in the world you can interact with

Clay's Broken Magic Compass
As mysterious as it is broken, which is to say.....somewhat.

Species - Playable/NPC
Homebrew details for species

Plasmoid - Additional Lore
Cold temperatures - doesn't shiver, protoplasm thickens (like differing degrees of flow)
Can consume rancid or rotten (within reasonable limits) food/beverages since they are acid/poison resistant
High alcohol tolerance from being poison resistant?
No sense of smell - has no smell receptors, instead they taste the air similar to how a snake flicking their tongue tastes the air.