Neo Cortex

Dr Neo Cortex is the principal villain in the Crash Bandicoot series.

Early History
It is made apparent that he was educated at Madame Amberly's school, which appears in Crash Twinsanity. He also has a niece named Nina.

Making his debut in Crash Bandicoot, Cortex planned to take over the world using superanimals evolved using his Evolv-o-Ray which was created by Dr N Brio (although it is later claimed he himself built it as a child). His plans were thwarted when a failed experiment defeated him and destroyed his castle.

Returning to Power
Afterwards, he decided to live in a space station with his new assistant Dr N.Gin, Brio having long ditched him to serve drinks at a bar. He lies to Crash, telling him the fate of the world is in peril and Cortex needs the crystals to put everything right. Luckily, Brio jumps in at the right time, and Crash gathers the gems instead of the cystals. Using a laser built by Brio, the gem power destroys the Cortex Vortex space statiom. In this appearance, Crash Bandicoot 2: Cortex Strikes Back, his skin is notably less yellow than other games.

The Great Uka Uka
The Cortex Vortex hurtles towards Earth and destroys a temple. It is revealed that Cortex was working on the orders of Uka Uka, a legendarily powerful witchdoctor whose soul was placed in a mask much alike his brother Aku Aku. Cortex is joined by Nefarious Tropy who bends time in order to gather ancient crystals. Crash and Coco intervene however, and destroy the Time Twister machine in the process.

Cortex later joins the good guys to fend off Nitros Oxide, a racer who plans to turn the Earth into a giant parking lot. Oxide is defeated, and Cortex returns to working for Uka Uka.

Not long afterwards, he is summoned to partake in a battle between good and evil. Lasergun in hand, and old buddies on his side (including oddly enough N Brio, who is supposed to have gone to the good side), the games commence. These events happen in Crash Bash, and are not to be considered as canon for the series.

Superweapon
At a meeting for the villains in the series, it is decided that Crash Bandicoot must be eliminated. Cortex unveils his perfect bandicoot warrior, Crunch. However, Crunch is defeated by Crash at every turn, even with the assistance of The Elementals on the evil side. Crunch is taken to the good side after Cortex's defeat.

Vicarious Visions games
Cortex decides to shrink the planet. Crash fights to return the planet to normal, and Cortex fails again.

Cortex is side-noted for N.Tropy at one point, Crash Bandicoot: N.Tranced. This does not last long.

Emperor Velo the 27th eventually kidnaps him and Crash, and force them to race for the fate of the world. Cortex intends to save the world only to enslave it.

Cortex would later team up with Ripto from the Spyro series to create a series of high-powered gnorcs. Both Spyro the Dragon and Crash team up to defeat the two villains.

Uneasy Alliance
Cortex teamed up with Crash once again to help stop his demented former pets Victor and Moritz who were his two parakeets before he placed the Evolv-o-Ray on them and sent them to another dimension. He often ended up as Crash's weapon, even a snowboard.

Finally, Cortex raced against the good guys to gain control of a race park where his new plans for evil could possibly commence.