He's a wild-eyed man with an unkempt beard, a raspy voice and an oddly, smelly, filthy brown and purple garment made out of some special fabric and possesses plasma burns and scorch marks all over it. His left eye looks like it's about ready to jump out of his head.
He seems to work for some mysterious person that he calls "my agent". If he is alive at the end of the questions and responded well to the Chosen One, he wants to change jobs because of the non-respect for his person and getting into car repair, saying "I hear that is where all the money is made these days".
The Bridgekeeper ask the Chosen One three questions to try to cross the bridge, as he is the guardian. One mistake on your part means death. If the Chosen One has sufficient intelligence, they can ask him a question during his third question in return, which kills him automatically due to his hesitation.
If the Chosen One has an Intelligence below 4, the conversation will be extremely confusing, but can still answer questions. The Bridgekeeper will ask only two questions and help the player character greatly for the 2nd, giving the answer in the question. Also, it's the only type of character that can kill the Bridgekeeper directly in the 1st question, asking him his name.