It seems he's the chief of the Nargor pirates and the owner of the tavern. He also gambles. You can bet from 1 to 99 gold and if the Die lands on 6 you get 5 times your bet. You may also bet 100 gp for a chance to win the Die. Similar to the main money gambling game, if the Die lands on 6 you will win it. He often ends his sentences with Har Har Har.
Klaus is an allusion to Klaus Badelt, composer of music to Pirates of the Caribbean: The Curse of the Black Pearl.
Player: hi Klaus: Ho matey! Player: name Klaus: I'm Klaus. Player: rum Klaus: There are people who would kill you for rum. Then again there are people who would kill you anyway. Player: raymond striker Klaus: Sooner or later he will run out of luck and then we will have his head. Player: liberty bay Klaus: We have a kind of trade agreement. They make the rum and we plunder it. Har Har Har. Player: thais Klaus: The Thaian people see themselves as the rulers of the world. If they only knew ... Har Har Har. Player: carlin Klaus: A city that is run by women. And those wimps in Thais have still not been able to regain control. Har Har Har. Player: venore Klaus: The Venoreans are the power of the future, trust me. Player: king Klaus: If I were the king, I'd fill my court with the most beautiful women of the realm. Har Har Har. Player: treasure map Klaus: I've already given you the complete map. Now you're on your own, matey. Player: pirate Klaus: Ah, the romantic life of a pirate. Fish for breakfast, storms for lunch and an early death for supper. Har Har Har. Player: excalibug Klaus: I guess it would come in handy to open some casks. Har Har Har. Player: ferumbras Klaus: Dead magicians are only good for frightening little children. Har Har Har. Player: bye Klaus: Whenever your throat is dry, you know where to find my tavern.