Runuganga

(sometimes incorrectly romanized as Lunuganga), is a giant Hollow who serves as the Guardian of the White Sands and acts under orders to protect Las Noches from intruders.

Appearance
Runuganga has a large, grey body and is made from sand. His arms are long, with the forearms being much thicker than his upper arms. Runuganga's head resembles a sand castle, while his Hollow hole is in the centre of his chest. He wears a low-slung cloth around his waist and decorated bracelets on both wrists.

Hueco Mundo arc
Runuganga blocks the passage of Yasutora Sado, Ichigo Kurosaki, Uryū Ishida, Nelliel Tu Odelschwanck, Dondochakka Bilstin, and Pesche Guatiche during their journey to Las Noches. The three friends from the Human World attack the Guardian relentlessly, but their attacks all fail, as they are similar and nature and, Runuganga can simply reform after being attacked by them. They are eventually saved by the arrival of Renji Abarai and Rukia Kuchiki. Rukia uses her Shikai's second dance, Hakuren, and defeats Runuganga. However, as a last act of spite, he opens a sinkhole that sends the group tumbling into the Forest of Menos.

Fake Karakura Town Arc
He appears once again in the anime while Sado and Renji fight off the Hollows. The Hollows stop spawning as Runuganga emerges from the sand. Knowing that he is immune to their attacks, they decide to fight him anyway, and as they do, Renji's Zanpakutō is nearly eaten until Sado pulls it out for Renji. Renji releases his Bankai, but still to no avail. Seeing their attempts becoming more successful however, a new, stronger body of Runuganga appears and enters the battle with an Arrancar-level Cero. Seeing just how strong Runuganga is now, Sado resorts to using his Brazo Izquierdo del Diablo and uses his La Muerte attack, noting the huge crack it caused in Runuganga's body. Runuganga slaps Sado away before the attack causes more harm, and successfully regenerates his body. He sees Sado use the same attack again, this time doing less damage, as he was expecting the attack. However, Renji jumps up and swings his Bankai at Runuganga's head, finally forming a huge crack along his body and defeating him.

Powers and Abilities
Sand Manipulation: Runuganga has the innate ability to manipulate the sand. He can use this ability to create massive pits in order to trap the group of Shinigami and Arrancar trying to infiltrate Las Noches. Runuganga can also create multiple tornadoes.

Regeneration: As seen in his battle with Ichigo, Chad, and Uryū, Runuganga has the ability to regenerate lost body parts and wounds, making him immune to most physical and Kidō attacks.

Unhinged Jaw: Runuganga also has the ability to widen his jaw to such a size as to swallow the entire group of his opponents in one fell swoop.

Multiple Bodies: Runuganga is said to have many bodies as he is basically just sand. Killing his individual bodies does not kill him as a whole.