Greatshells

The greatshell is a type of large crustacean-like creature, occupying many different environments on Roshar. Greatshells have antennae, shells, and violet blood that smells like mold. Many greatshells are far larger than any crustacean should be able to grow. Roshar's low gravity, high oxygen atmosphere contributes to their great size.

There are many different subspecies of greatshells. These include:

• Chulls are common greatshells, used as pack animals for pulling carts and other manual labour. 
• Yu-Nerig are aquatic greatshells in the depths off the coast of Marabethia. They are known for their succulent flavor. Many of the Reshi Isles are not actually islands, but island-sized greatshells.
• Chasmfiends live inland, in the chasms of the Shattered Plains. They can grow as large as fifty feet tall, have massive claws, an incredibly thick, stone-like carapace, and mouths full of barbed mandibles.