ZERO

ZERO (E-100) is a character that appears in Sonic Adventure and in the television anime Sonic X. Created by Dr. Ivo Robotnik, ZERO is tasked with hunting down a blue Flicky that is in possession of chaos emerald. Amy Rose bumps heads with the little bird at the beginning of her story in Sonic Adventure and promises to protect him. Throughout Amy's story, ZERO chases Amy throughout 3 stages, leading up to a final boss battle on the Egg Carrier.