Morrowind Mudcrabs
This species of mudcrab resemble large, brown stones. They use this disguise to both avoid predators and fool prey before attacking with their powerful jaws and pincers, which can inflict swamp fever upon victims.
The Redoran Manor District and Council halls in Ald'ruhn are located in a massive shell that once belonged to a mudcrab of incredible size. This type does not posses the ability to camouflage itself as a rock. It's also much more crablike in appearance compared to its Morrowind cousin, in that it has pincer arms instead of jaws. Its back is covered by rock-like bulbs. It can infect its victims with swamp sever.
Skyrim mudcrabs
Skyrim mudcrabs look like crabs, like their Cyrodiillic cousins, but are also capable