Ulquiorra Cifer

Ulquiorra is a slender, yet fairly muscular, male Arrancar of average height with a melancholic appearance, fairly short, messy black hair, grayish skin, a black upper lip, and green eyes with slit-shaped pupils. One of his bangs falls between his eyes, somewhat similar to Rukia Kuchiki, 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. They are somewhat similar to what Ichigo's inner hollow wears. However, his jacket seems to have longer coattails than others, and the collar is rather high. Like most other Arrancar, he possesses remnants of his former life as a Hollow in his appearance. His Hollow hole is located on his sternum where a heart would normally be (though initially for some reason, the hole was located on the base of his throat; a change that was seen in both the manga and anime). The remainder of his hollow mask lies on top of his head, forming a broken helmet. He is the fourth-ranked Espada, signified by the tattoo on the left side of his chest.

Source: Bleach Wiki