Flying Mud-crabs having battles with Dragons... In flight!? I want this to happen.. lol

There have to be mudcrabs.

I don't think there'll be more than one type, and it's not really necessairy, but variation never hurts.

I hope they won't be too aggressive too.

And I'd prefer them to look like in Morrowind, they kinda were cute in that game.
Plus Morrowind's mudcrabs look like they could handle cold temperatures better than Cyrodiil's.

I'd like there to be a quest with the reward being a domesticated mudcrab that you can keep, release into the wild, or cook.

I agree with the Morrowind mud-crabs being more suited to cold temperatures, looked much more stocky then their Cyrodiilic counterparts. But again in Skyrim, I think they should go with a new look perhaps inspired more by Morrowinds yet with a new unique style of their own.

Study your lore, the civil war in Skyrim was initiated by Daedric mudcrabs.

Mudcrab zombies that only come out at night and terrorize the villages and eat human brains and mudcrab-human hybrids and mudcrabs that ride dragons and command them as their pets

that would be terrifying

This is the premise of TES VI. A new realm of Oblivion is discovered -- the realm of mudcrabs. Oblivion Gates spring up and hundred of mudcrabs pour out, and when you enter you find thousands upon thousands. In the Sigil Room there is a queen mudcrab that releases more mudcrabs.

Speaking of mudcrab queens . . . whatever happened to those kwama from Morrowind? Kwama eggs are the chief export of Morrowind, but you never see them in Oblivion!