Rauborn

Rauborn is a barman that works in the Ratpit Bar, found in the Rat Pits beneath Keldagrim for Overgrown Cats. He sells stew and beer.

As he's located in the Rat Pits, you must have reached a certain stage during the quest Ratcatchers, more specifically in the part after you help Smokin' Joe, to talk to him.

Trivia

 * He looks identical to Drorkar.