Uva is one of the five Greeed, the major villains of Kamen Rider OOO.
True to his nature as a Greeed, Uva is extremely avaricious and full of an unquenchable thirst for possession that leads to consuming the world if unchecked. He is also the most hot-headed, rushing into things such as regaining his Core Medals or taking out his frustration on others.
As a Greeed, Uva can create insect Yummies from human desires with a Cell Medal, the Yummies he create use an ideal human's desires which pull themselves out of the bodies of their hosts, then seek out and physically consume the object of their progenitor's desire before molting into their complete forms, this is similar to how most insects mature. However, starting with his Ageha Yummy, this has changed to carrying out the desire of their host instead, though taken to an extreme fashion, and Uva typically remains in contact with the host to some degree. His human form is of a young man who wears a green leather jacket in order to blend in with society.
Powers original to him are jumping long distances, slice through anything, and discharge lightning from his horns. He is also so far the only Greeed to produce the weaker Waste Yummy either using them as an army to fight enemies or produce a large amount of Cell Medals.
When Uva gets a massive amount of Cell Medals in his body, normal attacks have little effect on him. In his complete form, Uva gains a stronger version of this immunity where even attacks powered by the purple Core Medals have no effect on him. Both of these abilities are very similar to the innate immune systems certain insects possess.
Uva, like the rest of the Greeed, was created 800 years ago through the Core Medals. Along with the other Greeed, Uva was sealed in a stone coffin until 2010, when Ankh removed the petrified OOO Driver. Learning that Ankh took one set of Kamakiri and Batta Medals, Uva creates the first two Yummies to find Ankh and produce Cell Medals for him. While fighting the current Kamen Rider OOO, losing another Kamakiri Medal and a Kuwagata Medal, Uva learns that the Kamakiri Medal Ankh ended up in the possession of Kazari. Learning Ankh's intentions with the Core Medals and considering it, Uva confronts Kazari about it until their fight was stopped by Mezool
In the aftermath of Kazari's scheme with Mezool and Gamel undone by their own Core Medals, Uva decides to act on his own so he can find his own form of evolution by amassing a large amount of Cell Medals while resurrecting Gamel and Mezool through their Core Medals. However, after witnessing OOO's Putotyra form in battle, Uva finds himself betrayed and destroyed with only the Kuwagata Medal holding his mind remaining. The Kuwagata Medal latched on a human host with Ankh helping to restore him as they join the other Greeed and Maki to regain all their Core Medals.
Eventually becoming a complete being, Uva overpowers both Kamen Riders Birth and Birth Proto-Type, as well as Eiji as OOO PuToTyra Combo and in Greeed form. However, once he absorbed millions of Cell Medals and gained the King's Medals, Eiji fights Uva as OOO until Maki intervenes and adds Core Medals he stole from the other Greeed into him, saving his life to make him into the new vessel of all the Core Medals. Not wanting to lose his mind, Uva runs off to maintain control. Eventually Uva stumbles into a motorcycle yard, pleading for help as he is destroyed from the inside out by the Core Medals as they formed the Medal Vessel from his remains which was later destroyed.