Shadow

one eye black, one red; cold to everyone, sharp teeth

Literally completely black eyes and red irises; nickname "dark"; sharp teeth

dark blue eyes; Sonic's older brother; kind to Sonic, but rude to others; sharp teeth

red eyes; no best friends; only soft with Amy; dislikes Sonic

green eyes; kind and sympathetic; best friend - Rouge; still trying to improve Surge's character

blue eyes; cunning and playful like a fox; bat, with white fur

Blue eyes; best friends - Sonic and Knuckles; two-tailed yellow fox; kind and sweet, and also very smart

emerald eyes; quick and agile, always active, kind to everyone

Crimson eyes; usually rude and cold with everyone, but can be soft towards Sonic