Uka Uka

Uka Uka is a floating voodoo mask spirit and the evil younger twin brother of Aku Aku, of whom he is the exact opposite; while Aku Aku is benevolent, long tempered, calm, patient and empathetic, Uka Uka is malevolent, bad tempered, impatient, bossy, grouchy and cruel, showing little (if any) happiness throughout the entire series. He is ultimately the driving force behind Doctor Neo Cortex's plot for world domination, and is frequently upset with Cortex for his repeated failures.

Pre-series history
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.

Crash Bandicoot 3: Warped
The rubble of the ruined space station 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. 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.

Crash Bandicoot: The Wrath of Cortex
In Crash Bandicoot: The Wrath of Cortex, Uka Uka scolds Cortex and the rest of the villains for their less-than-impressive evil productivity. Fed up with Cortex's incompetence, Uka Uka concludes that if global domination is to ever be achieved, Crash should be handled with personally. Deciding to use Cortex's new super-weapon to wipe out Crash Bandicoot, he revives the Elementals to act as the super-weapon's source of power and bring it to life. When Crash imprisons the Elementals, defeats the super-weapon, and brings it to their side, Uka Uka holds Cortex responsible and fires an energy blast at him out of anger, but in doing so causes their newly-built space station to overload, forcing Cortex and Uka Uka to evacuate. Their escape pod lands in the depths of Antarctica, stranding them both on a sheet of ice.

Crash Twinsanity
In Crash Twinsanity, Uka Uka is freed from a wall of ice, but is enraged to see that Cortex has teamed up with Crash in order to defeat the Evil Twins, and transforms into an Ice Titan in order to kill both of them. When he is defeated, Uka Uka attempts to flee, but Aku Aku stops him and tells him about the Evil Twins' plot to destroy the Earth. Opposed to the fact that someone else is trying to destroy the world (a job that he believes is his), Uka Uka temporarily teams up with his twin brother, only to be defeated alongside him by the Evil Twins' ability to warp reality.

Crash of the Titans
In Crash of the Titans, Uka Uka teaches Doctor Cortex a new process called "Mojo mutations", which uses a magical substance known as Mojo to mutate any living creature into a loyal minion of Cortex. At the Temple of Zoom, Uka Uka leaves Doctor Cortex to destroy Crash and Aku Aku while he returns to the base with an enormous amount of stolen Mojo and Coco Bandicoot at tow. When Cortex fails to defeat Crash, Uka Uka becomes furious and announces that he is replacing Doctor Cortex, much to the shock of his minions. In a lab on the island's giant tree, Uka Uka expresses his relief with Nina Cortex's higher competence, but begins to sense Aku Aku's presence nearby and decides to stay in the lab and kill Crash Bandicoot himself. Uka Uka confronts Crash as the penultimate boss by using Doctor Cortex's Evolvo-Ray on himself, giving him a gargantuan body made from the tree's wood. When the Evolvo-Ray is destroyed, Uka Uka claims that he will have the last laugh, as Nina is about to launch the Doominator, threatening the existence of Wumpa Island. Uka Uka is absent in the Nintendo DS version of the game.

Crash: Mind over Mutant
In Crash: Mind over Mutant, Uka Uka is subdued and placed in a milking machine by Doctor Neo Cortex and Doctor Nitrus Brio but he can be used as a source of the negative Mojo needed to control those using the mass-produced NV device, being fed cake continuously during this time ((Cortex tells him that he will never get another chance to have cake)). He is eventually freed by Crash and Aku Aku, and promises to take the two to Cortex's new space station if his magical bones are returned to him. When this task is completed, Uka Uka keeps his promise and warps Crash and Aku Aku to Cortex's space station as an act of vengeance against Cortex. If he is talked to after being set free, he gives Crash a mini-game to complete.

Crash Team Racing
Uka Uka appears in Crash Team Racing as a tutor for the characters Cortex, N. Gin, Tiny, and Dingodile, giving them useful tips and tricks throughout the game. He also appears as a power-up during the races, protecting the characters (along with Ripper Roo, Papu Papu, Komodo Joe, Pinstripe Potoroo and Doctor Nefarious Tropy) from all attacks and obstacles whilst giving them a speed boost. However, he cannot protect the characters from chasms and deep water.

Crash Bash
In Crash Bash, in order to resolve his constant fighting with Aku Aku, Uka Uka summons Cortex, Brio, Tiny, Dingodile, Koala Kong, and Rilla Roo as part of a contest between his players against Aku Aku's; Uka Uka is later forced to relinquish Tiny and Dingodile to Aku Aku's team to even out the number of players between them.

Crash Bandicoot: The Huge Adventure
Uka Uka oversees Doctor Cortex's plot to shrink the Earth in Crash Bandicoot: The Huge Adventure.

Crash Bandicoot 2: N-Tranced
Frustrated with Cortex's defeat in Crash Bandicoot: The Huge Adventure, Uka Uka entrusts Doctor Nefarious Tropy and N. Trance with a plot to recruit the Bandicoots towards their side. When Trance and Tropy are defeated, Uka Uka promises the Bandicoots a real adversary in the future.

Crash Nitro Kart
Uka Uka reprises his role from Crash Team Racing in Crash Nitro Kart, giving useful advice and acting as a power-up for the characters Neo Cortex, N. Gin, Tiny Tiger and N. Tropy.

Crash Boom Bang!
Uka Uka has a Cameo appearance in Crash Boom Bang! as a purchasable power-up.

Personality
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 Power 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. He's also a bossy, grumpy, grouchy, arrogant and bad tempered mask.

Outward appearance
Despite being the grouchy 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 obviously 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 his person (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.

Abilities
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 seiyûs 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.

Portrayals
In the English version of the series, Uka Uka is voiced by Clancy Brown (who also voiced Doctor Neo Cortex) from Crash Bandicoot 3: Warped to Crash Nitro Kart. In the English version of Crash Twinsanity, he is voiced by Alex Fernandez, who also voiced Farmer Ernest in the same game. As of Crash of the Titans, he is voiced by John DiMaggio (who previously voiced Tiny Tiger in Crash Nitro Kart) in the English version of the series. In the French version of the series, he is voiced by Christian Pelissier in Crash Bandicoot 3: Warped, Crash Team Racing and Crash Bash and is voiced by Laurent Nervest from Crash of the Titans onwards. In the Japanese version of the series, he is voiced by Ryūzaburō Ōtomo from Crash Bandicoot 3: Warped to Crash Twinsanity.

Trivia

 * Uka Uka is the first character other than Aku Aku to ever oerform an "assistance" role in the main continuity series. (This is shown in Twinsantity whenever he is summoned by Cortex or Nina. He is also an assistance option in CTR and CNK, but those aren't main continuity games, they're spinoffs.)
 * Uka Uka, whenever summoned by the player in Twinsanity, utters the same chant Aku Aku does whenever he is summoned. It is completely possible that Aku Aku, Uka Uka, and Papu Papu are from the same tribe since not only do the three characters share the same language, but Uka uses the same way of communication that Aku does, VIA a mask. Furthermore, Aku is a "witch doctor," a common native considered a sage. Since Uka is his brother, this implies that the brothers are from the same tribe. Since both of them are spirits residing in masks now, Papu is probably a decendant from their tribe, since they are dead already.
 * Many fans speculate that the reason Uka Uka is so evil is because his mother beat him. Seven fans believe that Radical Entertainment will soon touch upon this likely backstory.