Sir Roast McDuck was a male anthropomorphic duck who is now a ghost.
Sir Roast is depicted as an extremelly gluttonous duck, who died from overeating. He otherwise has the same tightwadish characteristics as all McDucks.
At his time, the McDuck clan suffered greatly as it had been impoverished due to Sir Stuft McDuck buying out Scotland from feudal subjection for 10,000 marks. Sir Roast McDuck further disgraced the clan when he broke into King William the Lion's pantry in 1205 and died from overeating.
As a ghost, Roast isn't keen on mingling with the matters of the living, and appears to have spent most of his time in the afterlife playing golf with the rest of the McDuck clan.