Sieghart

Sieghart, also known as The Green Knight (緑の騎士, Midori no Kishi), is a Vice Admiral in the Marines and the user of the Eme Eme no Mi. Spending most of his time at Marine Headquarters when not on a mission, Sieghart is also a temporary reserve member of the Shinan no Shisengumi (Shinan's Newely Elected Corps), a mini-faction within the Marines. Sieghart is also notable for his burning hatred of Monkey D. Dragon, due to an unknown incident in his past.

Devil Fruit
For more information, see: Eme Eme no Mi

Trivia

 * Despite his higher rank, Sieghart seems to often by scolded or put down by Rear Admiral Shinan, most likely do to his childlike mentality.