Mezool

Mezool (voiced by Yukana) is a minor antagonist in Kamen Rider OOO. She was the aquatic animal Greeed as well as the only female Greeed, and has aspects of the Shachi (killer whale/orca), Denki Unagi (electric eel), and the Tako (octopus).

While Mezool like the other Greeed, has little sympathy towards humans, she is the most kind of the desire powered Greeed, shown when she willingly shared some of her medals with Gamel and the others despite being incomplete. She serves as a mother figure to the others, as her desire is to know and feel true love, reflecting in her relation to Gamel and her human form of a high school-aged girl. However after she was stripped of most of her Core Medals, and the other Greeed decide to take matter into their own hands she loses dominance and control over them. She is very close to Gamel and after he goes through a mental breakdown and possessing too much power she absorbs him to put him out of his misery and make sure the power doesn't go out of control, but also to regain her Core Medals. However, upon receiving her full power, she discards him and goes off on her own in order to achieve her desire.

When Mezool was first created, she resided within the original 10 Core Medals along with the other Greeeds. But as the 10th Core Medal was taken away, Mezool was released from the Core Medals. She and the other Greeeds became the embodiment of greed. The First Kamen Rider OOO shouts "Happy Birthday" and takes their Core Medals.

Mezool joins up with the other Greeeds and agrees to take down the King together, in order to retrieve their Core Medals. The Greeeds manages to get their Core Medals back too, but even when they are in their full form they can’t take on the king. In order to defeat him, they resort to using Yummies created from the King’s greed. Uva, Kazari and Mezool creates the Cockroach Yummy, Lion Yummy and Whale Yummy, they are almost as strong as a full form Greeed because of the King’s strong greed. But none of this is enough as Ankh reveals that he was working with the King all along, but the King betrays Ankh and scans all Core Medals which sealed him and the entire Greeeds along with Ankh's right arm.

In modern times after the Greeed were released, Mezool with the other Greeed began their quest to become Multi King while at the same time get back their Core Medals and gain more Cell Medals through their Yummy. Mezool often keeps the other Greeed in line while fighting the present OOO, Eiji Hino whenever he interferes with her Yummies and had lost two of each of her Tako and Unagi Core Medals during their second fight when OOO assumed Litorartar along with her leg armor with Gamel helping her escape. She has since regained her Tako Medals thanks to Gamel grabbing them when OOO accidentally kicked the Heavy Mammal Greeed into Ankh in their second fight. When the Greeed decided to ambush OOO, Mezool was robbed of all but one of her Core Medals thanks to Kazari, making her revert into her human form, then fled with her Core Medals being used in an experiment on Gamel. When Mezool returned to the Greeed's hideout she was attacked by Uva, no longer having any power or dominance over him or the other Greeed and was chased by Uva's Waste Yummy until they were destroyed by Kamen Rider OOO, unaware of Mezool's human identity. When Gamel was suffering from an energy overload while looking for Mezool, she absorbed him to keep the power from going out of control regaining her complete form. Unfortunately she is overwhelmed by even more power, gained from both a large amount of Cell Medals and two of Uva's Core Medals becoming a Giant Greeed. At first Kamen Rider OOO has a hard time fighting against her until he receives help from Kamen Rider Birth and gains the two insect Core Medals to become Gatakiriba Combo and destroys her Gatakiriba Kick. When her Core Medals were released they were seized by Ankh, Kazari, and Uva.

Later, she has been resurrected along with Gamel by Uva in episode 36. However, after witnessing OOO's Putotyra form, Mezool subsequently betrays Uva and, along with Gamel, sides with Kazari.

Later, after Ankh gives her back her Core Medals to assume her complete form, spurred by Kiyoto Maki knowing it was a facade, Mezool leaves Gamel to achieve her desire by abducting mother/child pairs and sealing them in her Yummy eggs to suck out their love. With her full power, Mezool is able to counter Kamen Rider OOO Latorartar Combo before he uses the Toride Vendor and the Medagabryu to shatter a full set of her Core Medals. Mezool then dies as Gamel arrives in her final moments, with only six of her Core Medals left in existence.

A replica of Mezool, composed merely of Cell Medals unlike the original, was one of the four Greeed recreated by Foundation X, forming the Dummy Inhumanoids alongside four Museum Dopants. These eight Dummies were unleashed by Lem Kannagi and assaulted Kamen Rider OOO. However, alongside Fourze, OOO was able to set free the Seven Legendary Riders, who take on the battle against them. Ultimately, this fake Mezool was destroyed by Riderman's Rope Arm.

Mezool is resurrected by Doktor G and becomes one of Dai-Shocker's 12 commanders. In the final battle, when Dai-Shocker and Dai-Zangyack unite to face the combined forces of Kamen Rider and Super Sentai, Mezool is last seen being defeated by Red1.

When monsters are killed on Earth, their souls are sealed in the world within the Magic Stone. The Riders gather and attempt to defeat Amadum, who plans to liberate the monsters within the stone. After his troops are defeated, he summons many powerful monsters to stop them. The Mega Greeed can be seen among those. This Mega Greeed is quickly destroyed by the combined attacks of the Denliner, Castle Doran and various Kamen Riders.

Through the use of replicated Core Medals created by Foundation X, Kaisei Mogami unleashed copies of Mezool, carried by Gamel, and her fellow Greeed against Eiji Hino, Emu Hojo and Ryuga Banjo. However, the broken Taka Medal on Eiji's person allowed the original Ankh's personality to take over upon making contact with his duplicate body. By retrieving the Core Medals from the enemy Greeed as well as himself, Ankh enabled Eiji to transform into Kamen Rider OOO once again and defeat the Greeed.

In an event witnessed by Sento Kiryu, Mezool is seen fighting Kamen Rider Kabuto and was among numerous monsters whom engaged the first 18 Heisei Riders before being wiped out by the Vortex Time Break of Kamen Rider Zi-O BuildArmor.

Incomplete

 * Greeed Powers: As a Greeed, Mezool has superhuman powers and aquatic animal-like abilities true to the race she represents.
 * Mind Reading: Mezool can read the thoughts of her host to search trough their inner desires and create a Yummy based on it.
 * Yummy Creation: A Greeed herself, Mezool can create Yummies from human desires through Cell Medals, first become roe-like eggs, which indirectly feed off the human's desire while forming a "nest" that incubates over a period of time while the human indulges their desire, their presence mostly concealed until they hatch into their complete forms either all at once or one at a time.
 * Human Disguise: Mezool can disguise herself as a human. Her appearance is a high school-girl that wears either a sailor uniform, a blue coat, or a light blue shirt.
 * Cell Medal Transmutation: Mezool can turn her body into a mass of Cell Medals, them reforming it back to her original state.
 * Hydrokinesis: Mezool can manipulate and use waters in her attacks.
 * Liquification: Mezool can turn her body completely into water.

Complete

 * Greeed Powers: As a Greeed, Mezool has superhuman powers and aquatic animal-like abilities true to the race she represents.
 * Mind Reading: Mezool can read the thoughts of her host to search trough their inner desires and create a Yummy based on it.
 * Yummy Creation: A Greeed herself, Mezool can create Yummies from human desires through Cell Medals, first become roe-like eggs, which indirectly feed off the human's desire while forming a "nest" that incubates over a period of time while the human indulges their desire, their presence mostly concealed until they hatch into their complete forms either all at once or one at a time.
 * Human Disguise: Mezool can disguise herself as a human. Her appearance is a high school-girl that wears either a sailor uniform, a blue coat, or a light blue shirt.
 * Cell Medal Transmutation: Mezool can turn her body into a mass of Cell Medals, them reforming it back to her original state.
 * Hydrokinesis: Mezool can manipulate and use waters in her attacks.
 * Liquification: Mezool can turn her body completely into water.
 * Egg Imprisonment: Mezool can imprison mother and child pairs in her Yummy eggs.
 * Love Absorption: Once having her victims imprisoned, Mezool can absorb their love emotions. As this would lead to their death, a way to prevent this is to defeat her.

Trivia

 * TBA