Nel is a female arrancar that has light green hair in the manga, but in the anime she has blue hair with a slight green tint, a large scar coming down from her forehead to her nose, larger than average incisors, 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.
Her previous form is that of a big-breasted, full-figured woman (that appears to be in between her late teens to mid-twenties), 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. A large "3" is tattooed on her back, indicating that she was the former 3rd Espada.
As GodQueen of Arrancar, and Infinity Espada she wears pretty much the same thing as when she was 3rd Espada except she also wears a cape made from the green gown she wore as a arrancar child, also her mask has been repaired and the crack, the chunk of the jaw, and the missing teeth are colored in the green tinted-teal/turquiose blue, and her eyes are also the same color as her hair.