Sir Eider McDuck is a minor character of the Heroic Age.
The MacDuichs helped drive out the Saxons in 946 though Sir Eider MacDuich fell in battle. His serfes had deserted him because he paid them only 30 copper-pieces per hour.
Sir Eider MacDuich spends his afterlife playing golf with the rest of the McDucks. He is reluctant to give Scrooge another chance, until he learns that he will be the greatest tightwad in the world.