Dr. Cortex, who's real name is Dr. Neo Periwinkle Cortex, is Crash's creator and enemy.
A Big Mistake
Cortex first appear in PS1's Crash Bandicoot as the main enemy. Cortex was making a army of animals to conquer the world, but one Eastern Barred Bandicoot named Crash Bandicoot was wrecking his plan, so he kicked him out and made contiuned the rest of his plan. Both Crash and Aku Aku finished Cortex off.