Hatchan or called Hachi by most characters is a Fishman, who is a former member of Arlong's pirate crew; who is good friends with Kuroobi and Chew. He is also easily fooled and not very intelligent.
In the English dub of the One Piece anime, Hatchan was originally voiced by Sean Schemmel in the 4Kids version. In the Funimation version he is voiced by George Manley. In a lesser known English dub version by Odex Ltd Hatchan was voiced by Joe Murray.