How is Sonic the Hedgehog?

If you mean, "Who is Sonic the Hedgehog?", then he is a supersonic hedgehog from a fantasy version of our Planet Earth(many fans mistaken it for "Mobius") and is SEGA's mascot. He starred in the 1991 videogame, Sonic the Hedgehog for the Mega Drive/Genesis as a response to Nintendo's mascot, Mario in his game, Super Mario Bros for the Famicom/Nintendo Entertainment System. His best-friends are a yellow fox named Miles "Tails" Prower(his name is a pun to "miles per hour), a pink hedgehog named Amy Rose(aka Rosy the Rascal), and a red echidna named Knuckles(guardian of the Master Emerald). He was formerly 10 years old in the Classic Era but turned 15 when the Dreamcast Era began and so on.