Hooleer

Hooleer is enormous and bulbous-bodied, marked most by a single great eye that glows purple within the Garganta and yellow once outside it. Long tufts of hair, matching or close to its skin tone, trail down its back, and each of its fingernails takes the form of a Gillian mask.

Hooleer first lurks within the Garganta's gloom during the traitors' escape from Sokyoku Hill, waiting behind the mass of Gillian as Aizen, Gin Ichimaru, and Kaname Tosen are drawn upward by Negacion. Its real moment comes at the fake Karakura Town, where Wonderweiss Margela brings it into the clash between the Gotei 13 and the Espada. Dwarfing everything around it, Hooleer breathes out a gust that snuffs the fire prison caging the three traitors, setting them loose, then disgorges a swarm of Gillian at the Visored. Once the Visored finish off the last of that swarm, Mashiro Kuna destroys Hooleer with a single kick, prompting Gin to remark on how quickly Wonderweiss's favorite was felled.

Like all Menos it can open the Kumon, which it uses to help the defecting Shinigami depart Soul Society. Its signature power is Regueldo, a breath potent enough to extinguish the wall of flame conjured by Yamamoto's Ryujin Jakka, and one that Tosen said reeked of death. It can also generate Menos, pouring numerous Gillian from its mouth as a churning sludge of black fluid and masks that then split into individual bodies.