Erik the Whirlwind is a mercenary in One Piece. He is a non canon character, appearing in the anime only, being the main antagonist of the Warship Island arc. Here he is hired by Commodore Nelson to capture the famed Thousand-Year Dragon, a creature whose bones are said to be the source of eternal youth. However, Erik was only using Nelson to find the Dragon for himself for power.
First Appearance: Episode 54
(Source: One Piece Wiki)