Esmeralda has long black hair, purple eyes, and emerald green markings on her right cheek. She wears arm warmers on both arms, and a plated item on her wrist. She wears ragged black cloth over her white hakama. The remnants of her Hollow Mask are in her hair like a decoration and her hollow hole is just above her breasts. Like her partner, she wears her Zanpakuto on her back.
Despite her appearance, Esmeralda is a kind Arrancar. She dislikes fighting, though she is well suited for it, and cares deeply for the safety of her partner, Adolpho, and will try to protect him, even when he orders her not to. She seems to be the only one who knows about Adolpho's past and takes great pride in this, and will never share knowledge that Adolpho has shared with her in confidence.
Esmeralda was an Adjuchas level Hollow before bercoming an Arrancar. After her transformation, sh e encountered Adolpho, who clothed her and took her in as his partner. She traveled around Hueco Mundo with Adolpho, fighting more often than not on his behalf. She seems to genuinely care about Adolpho, though on what level is unknown.