Ulquiorra Cifer , pronounced Ulquiorra Shiffer in the English dub and originally romanized as Ulquiorra Schiffer,is Espada cuatro (4) in Aizen's army of Arrancar, and is one of the series' central antagonists, as well as one of Ichigo's main Arrancar rivals.
Ulquiorra is a slender, yet fairly muscular, male Arrancar of average height with a melancholic appearance, fairly short, messy black hair, pale white skin, a black upper lip, and green eyes with slit-shaped pupils similar to a cat's. Part of his bangs falls between his eyes, and he has distinctively thick eyebrows. He has teal lines that descend from his eyes, making it appear as if he is crying. His facial expression rarely changes, and he is almost always frowning. He wears typical Arrancar clothes: a white jacket, black sash, and a white hakama. However, his jacket seems to have longer coattails than others, and the collar is rather high.
His zanpakutō is named Murciélago (Spanish for "Bat"), (Japanese for "Black-Winged Great Demon"). Ulquiorra's Zanpakutō takes the form of a standard sized katana with a green handle and sheath. The guard has two curved extensions from its long sides, with a line going through both sides to give it an eye-like appearance.