Peterman is the leader of a kidnapping gang known as the Hound Pets, located in the Shabondy Archipelago. He learns from some bounty hunters, who were likely injured while attempting to attack the Straw Hats for their bounties, that a mermaid named Camie is at Shabondy Park. Peterman then negotiates a deal with them, offering 10% of her final selling price in exchange for information and leaves to kidnap her.
He subsequently takes her to the Human Auctioning House, intending to return later to collect his share once she is sold. However, he never gets the opportunity because the Straw Hats manage to rescue her and then raid his hideout, giving him a well-deserved beating for his crimes.
(source: http://onepiece.wikia.com/wiki/Peterman)
