Ganzack Pirates

The Ganzack Pirates were a group of pirates led by Ganzack. They only appeared in One Piece OVA.

History
The Ganzack arrive on the island and start taking people as prisoners

After the Straw Hat Pirates hear about "Devil Tower" they decied to sneak into the tower and see how the people are forced to work with threats to the lives of their families. Medaka charges in without thinking. She gets caught by the Ganzack Pirates see had seen earlier, but they quickly change their tone when Luffy pops up and demands food. Luffy and Zoro are cornered by the pirates who are armed. Then, surprisingly, a pirate is lowered down on a rope, tied to a motor and kidnaps Medaka.

Luffy chases after, to find out that it is Nami in a mask. Ganzack, with the appearance of a sea monster, has two crab claws on his shoulder. Ganzack grows selfish, arrogant, and angry whenever he is called "a crab". Nami says she is fine with him now, because he is "loaded". Ganzack urges Luffy to give up while he's still alive, with Luffy not willing to give up, Luffy begins to attack Ganzack. After falling to his knee's, Ganzack announces that he is going to be the Pirate King, yet Luffy beats him away and he crashes with the projectile he fired at the island.

Ship
The Ganzack Pirates possessed a massive warship built by Ganzack to achieve his goal of conquering the Grand Line. The ship is a massive, complex machine. Built beneath his fortress by the enslaved islanders, Ganzack unveiled the warship after putting down a rebellion. Ultimately, however, the joint forces of the islanders with Luffy, Zoro, Medaka, and Nami defeated Ganzack and sank the ship.

The warship was huge. In addition to spikes and cannons it has several special weapons. In the bow of the ship there was a chamber for the plesiosaur. On top of the fortress was a massive dynamite gun, a weapon was of mass destruction.