Several centuries before the events of the series, Uka Uka was locked away by Aku Aku in an underground prison due to his malevolent nature. Several millennia after his incarceration, Uka Uka recruited Doctor Cortex to fulfill his desire to enslave humanity, only to have Doctor Cortex lose the crystals and the gems, and have his space station destroyed.
The rubble of the ruined space station from Crash Bandicoot 2: Cortex Strikes Back eventually crash lands onto Earth, destroying the underground prison, and finally freeing Uka Uka. Upset with Cortex's failure to retrieve the crystals and the gems, Uka Uka recruits Doctor Nefarious Tropy, who has created the Time Twister, which will allow them to collect the crystals and the gems in their original places. And, since Cortex's failure also managed set him free, Uka Uka still felt a sense of gratitude and generosity for him. When Crash intervenes and destroys the Time Twister, Uka Uka is trapped inside a time prison with Doctor Cortex and N. Tropy, who have been turned into infants and are pulling and stretching him.
Uka Uka is a psychopathic villain with an inflated ego, believing that he is superior to the point that he often refers to himself as "The Great Uka Uka" in earlier games, though Doctor Neo Cortex and Doctor Nefarious Tropy have also referred to him similarly. Despite this, he is capable of rare generosity, namely when he spares Cortex's life after Cortex inadvertently sets him free with the ruins of his space station. In contrast, he seems to respect Nefarious Tropy for his greater relative competence. Uka Uka largely looks down on his older brother Aku Aku, whom he sees as feeble. It is implied in Crash of the Titans that he has fallen into a "shame spiral" due to his constant losses and that an earlier depression led to him engaging in bulimia. It is also claimed that he is extremely self-conscious about his lack of a body.
While Uka Uka's self-perceived purpose is to conquer or destroy the world, he is willing to temporarily save it from other threats as he considers the act "his job". In most of his appearances, he seeks to accomplish this by obtaining power from the crystals or gems. After Crash inevitably thwarts his plans, Uka Uka blames Cortex for their failure and attempts to magically assault him, an example of his tendency to blame others for his own mistakes.
Outward AppearanceDespite being the brother of Aku Aku, Uka Uka differs greatly from him in terms of physical appearance. Uka Uka is generally larger than his twin brother, and his "skin" is of a black color in contrast to Aku Aku's brown. While Aku Aku possesses a green goatee, Uka Uka sports a large red beard, which becomes a brownish color in later games. This beard is absent in Crash of the Titans, in which Uka Uka lacks the lower jaw needed to possess one. His nose is small and rectangular, as opposed to Aku Aku's long, pointed nose. Lastly, while Aku Aku has four to six feathers attached to his head, Uka Uka sports three bones; one is tied to his forehead, and two are seen dangling on ropes from both sides of himself (though they do not swing with his movements until Crash Twinsanity). Another notable feature is the yellow stripe located on his forehead. In Crash of the Titans, Uka Uka is shown to have undergone a drastic redesign, resembling a large red skull with pointed teeth, large eyebrows, white pupils, and an absent lower jaw. The bones upon his person have also doubled from three to six, with three bones hanging from large feather-like appendages on each of his sides.
Uka Uka shares many of his brother's abilities, such as flight and the ability to protect his wearer. It is hinted in Crash Bandicoot 3: Warped that he can possess his wearer, as shown by Cortex's reaction to Uka Uka being removed from his face; this is more emphasized in the Japanese version of the game, in which Doctor Cortex and Uka Uka's seiyuus speak their lines together while Cortex is wearing Uka Uka. It would make sense that Uka Uka is able to "jack" and possess people akin to his brother Aku Aku's ability in Crash of the Titans and Crash: Mind over Mutant. Uka Uka's main offensive ability is a small energy volt which he often uses to punish Doctor Cortex. He can also create an artificial body out of matter or energy through physical contact, as shown in Crash Twinsanity and Crash of the Titans, in which Uka Uka assembles bodies out of ice and Wumpa Island's tree respectively. However, this body shares any weakness its components did; for example, his ice-body is vulnerable to fire.
Role in the series
Like Cortex, Uka Uka's role in the SAFA world is still unspecified. However, in his eventual role, it is stated that, like his brother Aku Aku, his alternate form in Crash of the Titans is actually a more-powerful transformation that grants him more defense and offense, but to also augment his minions to fight better, as the source of this will be under specification in the future. Or he could possibly be a creation of Darkspawn origin.