Donquixote Pirates

The Donquixote Pirates is a group led by Donquixote Doflamingo, who goes by the underworld broker alias "Joker".

Past
Not much is known about the Donquixote Pirates before the timeskip, as the term itself did not come up until after. However, Trafalgar Law was once a subordinate whom Doflamingo treated as a younger brother before his defection. Vergo was apparently the first member of the crew, and Law's senior, but before becoming famous, he enlisted in the Marines to serve as a spy on behalf of Joker. The Bellamy Pirates also swore their allegiance to the crew, and was permitted to use its Jolly Roger; Doflamingo dismissed them when their captain was defeated easily, falling out of the expected standards.

At some point in the past four years, Doflamingo formed a three-way alliance with the rogue Marine scientist Caesar Clown and Kaido, in order to create SAD and SMILE artificial Devil Fruit, to create an army of Zoan-class users within the New World. However, needing Caesar for the SAD production and not trusting him, Doflamingo assigned Vergo and Monet to act as an intermediate and spy/guard, respectively.

Battle of Marineford
While Doflamingo himself participated in the Battle of Marineford, Law, having already formed his own crew and became an infamous rookie, came near the end of the war in order to rescue Monkey D. Luffy. Law succeeds in saving Luffy while Doflamingo emerges from the war unharmed. One year later, Law became a Shichibukai by turning in 100 hearts from pirates and sought shelter in Caesar's hideout, Punk Hazard.

Punk Hazard Incident
During the events in Punk Hazard, Law revealed his rebellion against the Donquixote Pirates by attacking the SAD production room and attempted to kidnap Caesar. Doflamingo ordered Vergo to brutally eliminate Law, but Law succeeded in defeating his senior and, indirectly, killing Monet. Doflamingo, in turn, sent Baby 5 and Buffalo to clean things up and retrieve Caesar, and, upon seeing that Monet failed to detonate the island's chemical weapon as ordered, decided to enter the island himself. However, Baby 5 and Buffalo are swiftly knocked out by the Straw Hat Pirates, and then Caesar was also captured after his failed attempt to escape alone to Dressrosa.

Taking Caesar hostage, Law cut apart Buffalo and Baby 5, and left their heads on the SAD tanker's rescue raft to drift towards the incoming Doflamingo, with a Den Den Mushi to contact him. Law threatened his former captain to forfeit his Shichibukai position with Caesar as the trade.

Crew Strength
The Donquixote Pirates is a very powerful crew, as their captain is a world famous pirate and a member of the Shichibukai with a former bounty of 340,000,000. Crew members Monet, Baby 5, and Buffalo are all known Devil Fruit users, while Vergo is a mole who has ascended the Marines ranks for about fifteen years, eventually becoming a vice admiral, while keeping his true identity hidden from everyone outside of his affiliates. They are in charge of the underworld brokering (including slavery, and production and distribution of weapons of mass destruction) in the New World, making them both very influential and very powerful. They are known to have destroyed entire towns at whim, as stated by Baby 5. The crew once also consisted of Trafalgar Law, a powerful pirate rookie who would become a Shichibukai as well with a former bounty of 440,000,000, prior to him leaving for his own interests.

Ship
The SAD Tanker (SADのタンカー) is a tanker used for carrying SAD from Punk Hazard to Dressrosa. It first appeared in Chapter 692, when Caesar smashed into it.

It is a paddle-wheel driven ship with three masts. At its bow is a spherical figurehead bearing the jolly roger of the Donquixote Pirates and a safety rail. Further aft of the bow are two large domed tanks with openings at the top, radioactive symbols on the sides, and hazard stripes around their circumferences. The masts are positioned immediately in front, behind, and between the tanks. They have dark sails and at least one of them has a crow's nest with a flag at the top. On the ship's hull is the Donquixote Pirates' jolly roger, the letters SAD, and an awning that partially covers the paddle-wheels. The ship is partly caked with Shinokuni since it was outside at the time of the gas's release. The hull also has two holes in it due to Caesar Clown crashing through it. The bridge is a flat, multi-story building with two buttress-like beams jutting out from the top. Despite its appearance, the bridge is actually quite spacious, as Law turned it into a sick bay so he could cleanse the imprisoned children of the drugs Caesar put in them. On either side of the roof are two small spires.

Usage
When Vergo heard that an SAD tanker was heading to Punk Hazard from Dressrosa, he caught a ride on a hunch. Upon learning about it, Smoker ordered his men to lead the children to safety and then commandeer the idling tanker.

Later, the tanker was covered by Shinokuni, but most of it was removed when Luffy's punch sent Caesar Clown crashing into it, which also put two holes in the hull. Franky was examining the ship in Franky Shogun, when he emerged and saw Buffalo and Baby 5 in the sky. He later fought them from the deck of the tanker. Two of the masts were destroyed during this fight.

Once the battle was over, the Marines commandeered the tanker in order to transport the children as well as the henchmen they had taken prisoner off the island. Franky was helping them repair the damaged mast, saying they should have told him sooner that the tanker was important. He said he would have moved the fight off the tanker's deck if he had known that it would be needed. Law gave the children treatment to detoxify their bodies in the bridge, which frightened Chopper. After seeing that they were all okay, he told them they would be going home. It was also in the bridge that the children were put in the custody of Tashigi and the Marines, the latter of whom tearfully asked Nami to leave the children under her watch. Soon after, Zoro and a child asked a Marine to get some alcohol and juice from the tanker so they could have it with the food Sanji was making.

Other Information
The Donquixote Pirates are a very powerful crew in both strength and influence. Being connected with the underworld, they have formed many alliances, ranging from brokering to spies within the Marines. They also managed to recruit significant individuals and entire pirate crews to become their allies, such as Caesar Clown and the Bellamy Pirates. Prior to the latter's dismissal, Bellamy and his crew were attempting to recruit promising pirates for the "New Age" under the Donquixote Pirates' insignia. The crew also formed an alliance with Kaido of the Yonko to create an army of artificial Zoan-class Devil Fruit users, which involves the SAD that only Caesar could produce. However, this alliance is based more on fear, as even Doflamingo fears Kaido's immense power, and goes into hysteria when the link was threatened.

In terms of interpersonal relationships, Doflamingo values the members of his crew somewhat like a family, albeit with tendencies of harsh punishments for failures; he saw Law and Baby 5 as though they were younger siblings, but demanded the former's death in the most brutal fashion possible for treason. He also abandoned Monet and Vergo when they were defeated, going as far as to order them to commit a suicide-bombing to take down all evidence and enemies within, though expressed his sincere regret for forcing them to do so; in turn, both Monet and Vergo, at least, were glad to give up their lives for Doflamingo, and happily bid him farewell. Doflamingo also treasures his alliance with Caesar, if only for the scientist's ability to produce SAD, but has no patience for other allies who fail to meet his standards, as he tortuously discarded the Bellamy Pirates and disowned the Human Auctioning House for respective reasons. The members refer Doflamingo as "Young Master" (若) as a sign of respect or by his alias "Joker" for discretion.

Similar to the Straw Hat Pirates and Big Mom Pirates, the Donquixote Pirates seem to have a wide and randomized variety of crew members, as opposed to many crews that follow a specific theme, ranging from a young girl to elderly people. Their base of operation is Dressrosa, a New World location with a luxurious mansion and a swimming pool, where they are only allowed to stay due to Doflamingo's position as a Shichibukai.