Naguri

First Appearance: Episode 498

Naguri is an anime-only character and former pirate captain that lived in the Gray Terminal twelve years before the current storyline. It is unknown where he is, or even whether he is still alive right now. He appears during the flashback showing the childhood of Luffy, Ace and Sabo, and saves them from a large rampaging bear.

(Source: One Piece Wikia)