Ankh (アンク) is one of the main characters in the series of Kamen Rider OOO. He is the bird Greeed and anti-hero/rogue throughout the series. Unlike his fellow Greeed, he has allied himself to the protagonist Kamen Rider OOO, mainly because of his inability to assume his full form and his lack of trust towards the other Greeed. However, when he regains his physical form, Ankh becomes OOO's enemy until he joins with OOO once again shortly before the final battle; Ankh was unable to kill Eiji due to emotions developed during the time he had spent with him, although his switching sides once more was contributed to his newfound capacity for feeling deeper emotions. He was attacked by Maki while defending Eiji resulting in the Taka Medal containing Ankh's consciousness being cracked. When he let Eiji use this Medal against Maki in the final battle, it split in half, but remained otherwise intact. His Core Medals are: Taka (Hawk), Kujaku (Peacock), and Condor.
Ankh is a dishonest wildcard. As a Greeed he has little regard for humans, seeing them for their flaws, with Eiji being one of the few exceptions. Ankh also believes that he has the right to get whatever he wants and detests having to give something away if there's no benefit for him. He is also at odds with the other Greeed, both because of the history he had with them, as well as stealing their Core Medals. He focuses only on obtaining enough Cell Medals to regain his body and to become Multi King. He has however been shown to repay debts to people, giving Eiji the means to become OOO, though this mainly because he wanted to use Eiji as a tool in his quest. Though Eiji plays him at times, Ankh prefers working with Eiji over with his fellow Greeed as the human is honest about his motives. He had since underwent a personality change, where he can no longer bring himself to harm Eiji or Hina without substantial reasons.
He serves as Eiji's companion and Medal Manager, supplying him with Core Medals stolen from other Greeed. Since possessing a human body, Ankh has been able to experience real emotions and the full effect of the five senses, something a Greeed is normally not capable of unless it possesses all nine of its Core Medals. The most prominent example of this effect is his ability to taste food, resulting in him developing a strong liking for popsicles to the extent of taking them without second thought such as taking them from a cart and making Eiji pay and scaring off children. True to his bird nature, Ankh also shows a preference for high places, frequently shown on trees, resting somewhere high in his quarters shared with Eiji, and jumping out of the window instead of going out through the door. Ankh avoids eating poultry due to his connection to birds.
He is also commonly seen carrying an iPad or an iPhone4 for gathering information and keeping track of the Core Medals. He is however not above betraying Eiji for his own benefit, whether it be regaining one of his Core Medals or joining the other Greeed to get new power while betraying the Greeed in a well formulated plan. Ankh's faith in this plan is so strong, he is willing to give the other Greeed all their Core Medals back unconditionally, a result of being spoiled by his experiences with human senses, which in turn fueled his growing disgust with his fellow Greeed.
In the Net Movie, Ankh was knocked out and his personality was changed.
As the Bird Greeed, Ankh is able to create a Bird-type Yummy, and deform into Medals and reform again and disguise himself as a human, the original Ankh's being the appearance of when he possesses Shingo while the lost Ankh's human form is a young boy with a red and black outfit with his right sleeve purple matching his blank purple skin. Even as his weakened forearm form, Ankh can fly through the air and pick up beings the size of humans, as well as summon items like Medals and OOO's belt and take control of bodies to use as hosts, as he did on Shingo with his hair becoming a dull blond and spiked up. He can also read his host's thoughts usually to look through memories regarding important information. Ankh can remain separated from Shingo's body, but in order to keep Shingo alive, the separation cannot exceed ten minutes. In Episode 36, Shingo's body is stable enough to survive on its own, but Ankh maintains control regardless due to the resurrection of Mezool and Gamel. After his counterpart is destroyed, Ankh regains all of his abilities that were possessed by his Lost counterpart. Later, he regained his original form called Ankh (Greeed Form).