Boa Hancock

The Pirate Empress Boa Hancock (海賊　女帝　ボア・ハンコック) is the only female member of the Shichibukai and was first mentioned by one of the Risky Brothers while he was talking about Mermaids to Sanji and Brook. She is the Snake Princess (蛇姫) of Amazon Lily and rules over it with her two younger Gorgon sisters, Boa Marigold and Boa Sandersonia.

Appearance
Compared to the abnormal appearance of her sisters, Hancock is a slender, tall woman with long hair dressed in a one-piece outfit. This beautiful appearance is noted by many throughout the world: to one of the Risky Brothers, her beauty is second only to that of the mermaids, while Marguerite claims she is the most beautiful woman in the world. Like every Shichibukai member, she has an animal theme: snake.

Personality
Hancock is a selfish, pompous and spoiled person who is used to having her own way, although she does lie to the World Government about her agreement to wage war with Whitebeard simply to get them off her back temporarily. She justifies her actions by her beauty and thinks that she can get away with anything because of it. While a member of the Shichibukai, Hancock doesn't think much of the World Government and would rather keep her title but not go to war or perform certain duties if she had to, preferring to use her position to presumably nullify her former bounty and to protect her home from the government who sees all of the Kuja as pirates. She doesn't think twice about killing her so called Marine allies.

Abilities and Powers
Ruling beside her sisters, Hancock has power over Amazon Lily and the rest of the Kuja women. As the Empress and Captain of the tribe, she is possibly the strongest Kuja warrior.

Apart from her great beauty (which seems to have a mesmerizing effect on both men and her fellow Kuja alike), Hancock has the ability to turn people into stone. This occurs when her hands form a heart shape, and beams are shot out of the shape. Anyone with "dirty thoughts" will be turned into stone. As demonstrated by Vice-admiral Momonga, the effects can be countered when the intended victim focuses their mind on other aspects such as pain, blocking out the "dirty" thoughts. This ability appears to be a Devil Fruit power as she uses the words "Mero Mero Merrow!" which is a typical way of using a Devil Fruit based attack.

Past
At some unknown time she became a Shichibukai to make a treaty with the World Government, that would keep her island safe, since they considered all on the island for pirates.

Trivia

 * Boa Hancock has several comparisons to the Greek character Medusa of the 3 Gorgon sisters. Medusa was said to be so ugly that those whom gazed upon her were turned to stone. Her ugly appearance was due to the jealousy of the Goddess Athena who discovered the beautiful Medusa with Poseidon in her temple in the midst of sexual intercourse.  Athena had reshaped Medusa so that Medusa match the other gorgon sisters, one noted part of the transformation was to make Medusa's hair into snakes which links to the Kuja's theme of "snakes".
 * Her ability to seduce other men is a reference to Sirens, which would fit her abilities, as a Siren would seduce sailors and lure them to a watery doom.
 * She is the only female Shichibukai.
 * She is one of two women who have claimed to be the most beautiful in the world, the other being Alvida.