Pícaro

Pícaro is not one being but a crowd of roughly two hundred child-sized Arrancar, each draped in a tattered cloak. Beyond that shared garment they look wildly different from one another, sharing no common face or form. The one that speaks for the group and acts as its leader is set apart by mask fragments shaped like headphones and a habitually bored, listless expression.

As a band made up of Arrancar children, the swarm thinks and behaves like one. They would far rather 'play' with those they meet than hurt or devour them, though in their skewed understanding, chasing an unwilling victim and pelting them with Cero counts as play, which makes them easy to redirect by simply promising a game later, as Yachiru Kusajishi once did. Their innocence also shapes how they read the world: instead of Hollows against Shinigami, they sort everyone into good people and bad people, refusing to eat the good and readily siding with a kind Soul Reaper over a wicked Hollow. That instinct is what led them to help Don Kanonji, who had shown them kindness, bring down Sōya Azashiro.

The group began as human children who were cast aside and left to starve. In death they turned into Hollows and eventually merged into a single Gillian, one that grew lonely and guilt-ridden over having consumed its own fellows. After maturing into an Adjuchas, it went looking for companionship by seeking out other dead children, converting each one into a Hollow and then either sharing portions of its own body with them or drawing them into the collective mass. While Baraggan Louisenbairn held sway, the swarm roamed the worlds freely, and once Aizen seized control he raised them to the rank of Espada. They were later demoted to the Privaron Espada as the 102nd, after which Aizen set Runuganga to keep them penned inside Las Noches so they would not cause chaos in the living world. As a former Espada the collective is formidable: its members draw on a shared pool of Reiryoku, funneling extra energy toward any one of them in danger, and every last child can loose a Cero at the same instant, enough combined force to gouge a wide crater across Hueco Mundo's desert floor. Their released form, Langosta Migratoria, sprouts transparent wings across the entire swarm and knits their minds almost into a single consciousness.