Yainu Nugire

Nugire Yainu was the name of the Black Cat crewmember (their shipwright) who was killed three years earlier by Marines. He was hypnotized by Jango to believe he was Captain Kuro, to whom he bore a passing resemblance. His name isn't mentioned in either the anime or manga but was later revealed in the One Piece Blue Data book. (Source: One Piece Wikia)