Uka Uka

Uka Uka is Aku Aku's evil twin brother.

Prior to Crash 3
There is a lot of history known about Uka Uka prior to the series (more than any other character). Eons ago, Aku Aku locked him in a prison to keep his evil ways away from the world. However, Uka Uka still wanted to spread his evil. He communcated with Dr. Neo Cortex and told him to make a mutant army (though the manual of Crash 1 states that Cortex's incentive was to shut up the people who ridicule him).

Crash 3
In Crash Bandicoot 3: Warped, Cortex's space station (which was destroyed in the previous game) plummets down to Earth. This sets Uka Uka free from his prison. Aku Aku senses this, and warns Crash and Coco. Meanwhile, Uka Uka is angry at Cortex for failing him twice. Cortex blames this on Crash, but Uka Uka doesn't want excuses. However, since Cortex's failures were what set him free, he spared him of any punishments. He recruits Dr. N. Tropy to help Cortex. This fails when Crash and Coco make it to their headquarters. Uka Uka brawls with Aku Aku while Crash fights Cortex (during the fight, this means the player can't have Aku Aku for protection, so they will always die in one hit). In the end, Cortex and Uka Uka lose. The Time Twister machine, which Tropy had built, goes haywire, sucking Uka Uka, Cortex, and Tropy in a portal. Cortex and Tropy are transformed into babies, fighting over possession of Uka Uka in a game of tug-o-war.

Crash Bandicoot: The Wrath of Cortex
In Crash Bandicoot: The Wrath of Cortex, Uka Uka is upset that the villains keep failing him. When he hears of a secret weapon Cortex is working on (Crunch Bandicoot), he becomes excited. He recruits the Elementals to power Crunch. In the final battle, Uka Uka assists Crunch and Cortex while fighting Crash. Crash defeats Cortex, and Uka Uka is furious at him. He fires a blast at Cortex, which hits a vital part of the space station they're in. This also sets Crunch free. While the bandicoots escape the doomed space station, Uka Uka yells at Cortex for ducking out of the way, which caused the blast to hit the part of the space station. In the end, it is revealed that they escaped it, but they are stranded on a chunk of ice somewhere in Antarctica.

Crash Twinsanity
Three years after the events of Wrath of Cortex, it is seen that Cortex and Uka Uka are frozen in a block of ice. While Cortex thaws quicker, Uka Uka remains frozen. About halfway through the game, Uka Uka is accidentally set free. He is angry at Cortex and Crash, and so, he creates a body out of ice to attack them. However, thanks to Crash and Cortex working together, his new body is melted. Aku Aku then informs him about the Evil Twins and how good and evil must work together to stop them. Despite this, they are defeated easily by the Evil Twins.

Crash of the Titans
In Crash of the Titans, Uka Uka informs Cortex of Mojo mutations. However, when Cortex fails to defeat Crash once more, Uka Uka becomes fed up with Cortex's constant failings. He fires Cortex and puts Nina Cortex in charge. When Aku Aku and Crash confront Uka Uka in his base, he uses the Evolvo-Ray on himself to give himself a body again. Crash defeats Uka Uka and tricks him into destroying the Evolvo-Ray.

Crash: Mind Over Mutant
In this game, Cortex and Dr. Nitrus Brio use his Mojo to power their NVs. He is later freed by Crash and tells him where the scientists' space station is.

Other appearances
He is the version of Aku Aku for the bad side in Crash Team Racing, Crash Nitro Kart, and Crash Twinsanity. In Crash Bandicoot: The Huge Adventure, he is only seen in the opening sequence, yelling at Cortex for his failings. In Crash Bandicoot: N-Tranced, he makes Tropy the leader since Cortex is stuck in a space station. He is a purchaseable power up in Crash Boom Bang!