Morrowind:Mudcrab (merchant)

The Mudcrab merchant is a friendly talking mudcrab who can be found on a small island just to the east of Mzahnch in the Azura's Coast region. The closest settlements to his location are Vivec to the west and Suran to the northwest. He sells several beverages and apparently has "a serious alcohol problem".

He is notable for being the richest of all merchants in the game. Along with Creeper, he is one of the only two non-hostile creature merchants, meaning that he will buy and sell items at their base value, rather than adjusting their prices according to Disposition and Mercantile skill as NPC merchants do.  

The Mudcrab merchant deals in fewer goods than Creeper, though he makes up for it by having more money to barter with. Still, if 10,000 gold still isn't enough to sell some of the more valuable items, there is a way to work around it.

As a creature, Mudcrab is one of the few merchants who will purchase skooma (but not moon sugar, since he doesn't deal in ingredients).

 
Dialogue
Background: ''"Whaddaya think? Sheesh. I'm a mudcarb... crab. Shure. A mudcrab. Thas me. Pretty sure. I LOOK like a mudcrab, right? Mush be. Thish IS me talking, right? So? I mush be... A talking mudcrab. And I sells stuff, right? So? I mush be a talking mudcrab merchant. Stands to reason, don't it?"
Greeting: "'How dry I am... how dry I am... nobody knows... how dry I am....' SHAY! Hi. There. Lesh make a deal. I got... stuff. Lots. Here. See?"
Talking mudcrab merchant: "Sure. Thash what I said? Did I stutter or shomethin? Talking. Mudcrab. Merchant. Read my lips. Ehr. Mouthparts? Read my mouthparts? Shomethin ain't right. But never mind. Jush one-a life's little myshteries. So. You gonna buy shomethin? Or sit here jawin' all day."''

Notes
To work around his gold limit, sell him cheaper items first, then wait a day. Come back and buy the cheaper items back from him, and then use his temporarily increased gold to sell the more expensive things. You can then sell him back the cheaper items the next day.
While the Mudcrab merchant has twice as much gold as Creeper, the former has the disadvantage of being located in the wilderness, meaning that resting 24 hours to replenish the merchant's gold will be subject to constant interruptions by creatures attacking.
Be careful not to kill him by accident, as he is indistinguishable from an ordinary Mudcrab until you enter dialogue with him (he is labeled "Mudcrab"), and is located in an area where there may be other Mudcrabs nearby.
The Mudcrab's inventory is known to sometimes reset, i.e., all the items you have sold him will disappear forever. Don't sell him anything you aren't willing to lose, such as quest-required items. This primarily—and possibly only—affects the Xbox version of the game.
The Mudcrab merchant can be guided to a more convenient location using Command Creature spells, most efficiently cast with an enchanted ring or other item (the direct casting cost of the spell is unusually high). Fortify Speed spells and, as needed, Water Walking  or Swift Swim help to speed him along. If you use a Command spell to have the Mudcrab follow you all the way to a fast-travel means (ship, silt strider, guild guide, or propylon chamber) then he, like other creatures under such circumstances, will follow you to the next destination if he is under the spell's effect and is nearby when you activate fast travel. If you have already sold quite a few items to him, he may be too encumbered to move. Like other followers, he will attack anything that attacks you, usually resulting in his swift demise. Thus, it is best to clear your path of enemies before attempting to take the Mudcrab merchant any significant distance.  As you traverse outdoor cells, various hostiles you have killed earlier in a cell may respawn when you re-enter it, especially if you have removed their corpses.  He does not have your Agility level, and is easily harmed or killed by short falls, nor can he climb steep slopes.  Finally, he is too large in circumference for some otherwise obvious transport venues; e.g., he will not fit on the narrow Vivec Gondolier ramps (if you're trapped in this situation, Levitate on Target will fix it), nor down the short stairwell at the Caldera Mages Guild, and his path is easily blocked by NPCs, rocks, etc.
If you ask Kaye for a little secret, he will mention an associate that wanders shores looking for opportunities and found someone on Azura's Coast with a lot of money to spend and was frazzled by it. This is likely a hint about the Mudcrab merchant.
M'Aiq the Liar will also acknowledge the Mudcrab merchant's existence if you ask him about the "talking mudcrab merchant" topic. He will also claim that there are more, saying: ''"They've got all the money. Mudcrabs taking over everything. They already run Pelagiad."
The Mudcrab Merchant also makes a reappearance in Legends as both a character in the Isle of Madness'' story expansion and as a card in the Houses of Morrowind card expansion.

Wares