Tora
Tora (トラ) was a member of the ANBU, working directly under the supervision of the Second Hokage. He was one of the ANBU ordered to watch the Uchiha clan to keep them from rebelling again. Tora is likely not his real name, but a codename. He was said to be very skilled. Endowed with tiger-like strength and walking ability, any target he aimed for had no hopes of escape. (Source: Narutopedia)