Kuroobi

Kuroobi is a ray fish-man and an officer of the Arlong Pirates, who was once a member of the Sun Pirates. He is one of the major antagonists of the Arlong Park Arc.

As a fish-man, Kuroobi possesses great strength. As one of Arlong's direct subordinates, he holds great authority over his crew.

Fish-Man Karate
Kuroobi practices Fish-Man Karate to fight his opponents. He is a level 40 black belt practitioner of this martial art, causing great injury to Sanji in their battle. As a fish-man, Kuroobi has an advantage underwater. Kuroobi states his ultimate technique is Senmaigawara Seiken but it is unknown actually how strong this punch is, as Sanji beat Kuroobi into submission before Kuroobi actually executed the move.

Weapons
He is also an adept swordsman. Eight years ago, when Arlong was about to kill Bell-mère and abduct Nami, Kuroobi blocked the bullets from Genzo and swiftly slashed his body with a cutlass.