If you're talking about Brawl, he's a standard character. Any other game (Super Smash Bros. the Original or Melee) you would have to hack into and make a character like Meta Knight (which I have no clue how to do).
Meta Knight is a starting character and therefore does not need to be unlocked.
spyro is not in super smash bros brawl but he did become Mario to find out watch spyro 3 revence of Mario
Beat Classic or Adventure mode with Mario on any difficulty.
Harjhot and aihsaa
you need to unlock a few characters involving Jigglypuff, Falco, and Dr. Mario.
Yes, you can get Mario Brothers Smash Melee and other Mario games for the GameCube.
no, but you can unlock Dr. Mario in Super Smash Bros. Melee by completing Challenge Mode with Mario.
You don't unlock him! If you unlock Sonic and play as him, Super Sonic is his final smash.
There is no such thing as Sonic Smash Brothers.
There is no such game as "Super Mario Smash Brothers." You may be thinking of Super Smash Bros., for which you cannot get Nook (Tom Nook, you mean?) in.
you cant
The rarest character in Super Smash Bros. Brawl is Mario the plumber. You can only unlock him by completing 1,000 Brawls and finishing the Subspace Emissary.