Duke is one of Peter's co-workers when he moves out of the mailroom at the Pawtucket Brewery to a job driving a forklift in "Peter Problems". Peter bets him that he can drink an entire vat of beer hoisted by the forklift and proceeds to do just that. As the other workers cheer him on, Duke is the first to notice that the flood of alcohol is beginning to threaten Peter's life as he struggles to keep up.

Duke is voiced by Danny Smith.