Nelliel Tu Odelschwanck

, otherwise known as, is a small, good-natured, childlike arrancar. She lives in the desert of Hueco Mundo with her adoptive hollow brothers, Dondochakka Bilstin and Pesche Guatiche, and their pet, Bawabawa. She has light green hair, a large scar coming down from her forehead to her nose, and a pink line that stretches horizontally across her face right below her eyes. The remains of her hollow mask make up a cartoonish skull on the top of her head. A crack runs along the left side of the mask and four of the teeth on it are broken off. It is currently unknown where her hollow hole is. Her clothing consists of a simple green gown.

Nel's appearance is in stark contrast to her vocabulary, which contains a number of bizarre phrases and words one wouldn't expect such a small child to know, such as calling her uvula a "throat penis" and referring to herself as a masochist. Ichigo Kurosaki assumes her hollow companions are responsible for this. Nel and her companions also represent oddities among hollows. Though most hollows are evil, Nel actually fears shinigami, assuming they are in fact the evil ones. In spite of this, she develops an attachment to Ichigo and follows him into Las Noches.

During her trip into Las Noches with Ichigo, Nnoitra identifies Nel as a former Espada during his battle with Ichigo, one who he found to be very annoying. Having been defeated many times by Nel, Nnoitra teamed up with Szayel Aporro Granz and attacked her from behind, causing the damage to her mask in the process, before throwing her into the desert. The same trauma apparently gave her amnesia, hence her lack of knowledge about her former life. When Nnoitra breaks Ichigo's wrist, Nel's concern causes her to spontaneously transform into her previous form. Her previous form is that of a fully-grown woman with longer hair but otherwise similar features. Her skull mask changes slightly, its features appearing sharper and less cartoonish with a pair of curved horns, while her hollow hole is still hidden from view. Although having grown up physically, she still seems to have her child-like affection over Ichigo, when she suddenly hugs him tightly after attacking Nnoitra, without realizing that Ichigo was losing consciousness. A large "3" is tattooed on her back, indicating that she was the former 3rd Espada.

Zanpakutō
Nel does not carry a zanpakutō in her child form, but has the unique ability to swallow enemy attacks and fire them back with powerful force exceeding that of the original hit, indicated by the eyes on her skull mask glowing (as well as being able to accelerate her movements with what seem to be a rudimentary form of Sonido). She also has the ability to heal others with her vomit (which she believes to be saliva). In her original form, she carries a zanpakutō with a green sheath and a hilt shaped like two crescent moons joined together at each other's back. Her speed and strength are greatly increased as well, fitting with her former position. She retains her attack absorption ability in her original form, and also performs it with greater ease. According to Nnoitra, Nel's trademark is to absorb an incoming cero and fire one of her own while returning it, thus creating a "double cero". While her child form severly limits her Arrancar powers, she is still powerful enough to absorb and re-direct a cero blast from a Privaron Espada-class Arrancar, though the effort seems to tire her immediately. The name of her zanpakutō is "Gamuza" (Japanese for "antelope knight"), and its release command is "declare". In her new form, Nel takes the form of an ibex-like centaur, with horns, armor, and a tail. Gamuza itself transforms into a double-ended lance. The only attack she has used in this form so far is "Lanzador Verde" (Spanish for "green spearman"). Nel throws her lance at her opponent with extreme speed and it drills into her enemy. Nel was changed back into her child form before she could finish Nnoitra off, though not before injuring him.