Duke of Nuts

The Duke of Nuts is the ruler of the Duchy of Nuts. In "The Duke", he is blamed for turning Princess Bubblegum into green and hairless, but he actually didn't. Princess Bubblegum claims that he's a bad guy, which causes Finn and Jake to chase him. Fortunately, he is actually a kind guy with a secret. He has a rare condition which makes him have a pudding deficiency. This causes him to constantly eat pudding from Princess Bubblegum's pudding pantry, which is why she hates him. Finn tells the Princess about the Duke of Nut's deficiency, but she doesn't believe him. He is shown to have suffered a "pudding overdose" before. His wife is the Duchess of Nuts, who believes that he has gone rancid. He has a son named Marquis of Nuts, who seems to be willing to do anything to save his father from death. In "Henchman" he is throwing a birthday party for another son known as Second Nut Son. He has a strangely high voice for a grown man.

Trivia

 * Lisby the Cashew Butler is his butler.
 * He appears to be friends with Marceline, although their history has not been revealed.
 * According to character designer Natasha Allegri, Peanut Princess is related to the Duke and Duchess of Nuts as either their daughter or neice.