You can't. But in Super Smash Bros Brawl you can unlock him by completing Classic mode with ten characters. Then defeat Sonic and you will unlock him and Shadow as an assist trophy.
No
You can't get sonic in SSBM only in SSBB and in SSBB you get him at the subspace emissary near the end
no.
No , Only In SSBB
Most people got it from a Nintendo magazine in April about Sonic joining SSBM, but it was an April Fools joke...
Complete the main storyline.
sonic and toad
You can't get sonic in ssbm!!
You can't, you can only unlock him in SSBB.
No, you can't. But you can play as sonic in Super Smash Bros. Brawl, for the wii.
They can't be unlocked. That was just an April fool's joke.
you need to beat sonic in green hill zone in brawl mode