Will knuckles be in Super Smash Bros. brawl

While Knuckles the Echidna does make a cameo in Green Hill Zone (along with Tails the Fox & Silver the Hedgehog) you can find a trophy of him along with most of the Sonic cast that has a brief summary of the character.

Additionally, unlock any of the afformentioned trophies randomly through Classic Mode, All-Star Mode or the Coin Launcher Mini-Game.