Shadow the Hedgehog (シャドウ・ザ・ヘッジホッグ, Shadou za Hejjihoggu) is a character from the Sonic the Hedgehog series who, like Knuckles, has a bit of a rivalry with Sonic. He is known as the "Ultimate Lifeform".
In Super Smash Bros. Brawl
Shadow appears as an Assist Trophy and uses Chaos Control to slow time down (similar to the Clock item).