Elvis "The King" Presley was an American singer, actor, and cultural icon who appeared as a ghost in the Season Sixteen episode, "Going Native", though he has been referenced a number of times throughout the series before.
He later appeared as a Elvis Presley Hologram in the Season Eighteen episode, "#HappyHolograms", as part of the Washington Redskins: Go Fuck Yourself Holiday Special.
When the natives were giving Butters and Kenny a tour of Hawaii, they tell them not to enter the Coco Palms Resort, and that is rumored to be haunted by "The King". Later, when Kenny is washed ashore, he finds the Coco Palms Resort and goes inside. There, he meets Elvis who he leads Kenny to a room that has shelves of vodka and pineapple juice on them, the ingredients for the native beverage chi-chis.
Elvis Presley has very distinctive black hair and sideburns. He appears wearing glasses and his white "American Eagle" jumpsuit from his famous Aloha from Hawaii concert.