He is the 18-year-old leader of a high school gang called the Pharaohs and is shown to dislike Max and P.J. seeing them as "dweebs" (completely regardless of the fact that they aren't from his school, nor are they even teenagers), and tries to keep them away from coming to Burger Behemoth, by which he calls "The Pharaoh's Turf".
Duke is also shown to have romantic feelings for Max's cousin Debbie going as far to ditch his own girlfriend for Debbie instead. He is finally dethroned as "King of the Pharaohs" after he loses to Max in a skateboard race.
Duke is shown to have a 1950s look with a brown Elvis hair style and wearing a navy blue jacket, white vest, brown jeans and black shoes.