Runuganga

, is a giant Hollow made of sand whose head resembles a sand castle.

Character Outline
He is the Guardian of the White Sands, and acts under orders to protect Las Noches from intruders. Being made of sand, he's immune to most physical and Kidō attacks, simply regenerating from any wound. He can control the sand around him to attack, creating sinkholes and tornadoes. Though this makes him practically unstoppable in Hueco Mundo's desert terrain, it also makes him extremely weak against water, and he is easily dispatched by Rukia Kuchiki using her Shikai. In the anime, Lunuganga is said to have many bodies since he basically just sand; killing his easily-dispatched, individual bodies does not kill him as a whole.