Abominations

Origins
There are creatures on Erwt that defy the rules of common sense, and which generally don't follow the ordinary rules of physics. They come from the deep Ocean, where the difference between air and water, light and dark is indistinct. Most of them stay out there; their constitution doesn't stand up to the more rigid fabric of Erwt, and turn back when they encroach on the calmer waters near the coast. These are the abominations. Creatures that survive near or on the mainland of Erwt are dragons, monsters, beasts, or simply animals.

Known Abominations
Tentacle horror - "Taller than the mountains of Gutreal, blacker than ink, it stood. Uncountable tentacles reached out, each one extending a thousand tentacles again, sweeping broadly through the air. I saw great, ragged wings, as from a lizard, hanging limply in a momentary flash of lightning. One tentacle came close; it was just a thin one, about the width of a grown oak, with barbs and orifices. Finer tentacles grew out from those vile orifices.", from Over the Edge.

Fanged jellyfish - "A great swarm of fanged jellyfish spilled up on deck. A minor scratch from their jagged fangs was sufficient to reduce the strongest of men to a whimpering child, some evil toxin gnawing at the wound.", from Over the Edge.

Deep lurker - "A great glowing eye stared up at us, a few meters below the surface.", from Over the Edge.