Who is Wolfsheim? What is unusual about him?

A notorious underworld figure, Wolfsheim is a business associate of Gatsby. He is deeply involved in organized crime, and even claims credit for fixing the 1919 World Series. His character, like Fitzgerald's view of the Roaring Twenties as a whole, is a curious mix of barbarism and refinement (his cuff links are made from human molars). After Gatsby's murder, however, Wolfsheim is one of the only people to express his grief or condolences; in contrast, the socially superior Buchanans fail to attend Gatsby's funeral.