For those of you who have played the Mother/Earthbound series, rejoice as Smash Bros for 3DS (and possibly Wii U) is getting its first Mother 1/EarthBound 0 stage. The stage will have gimmicks and there will occasionally be a rip in the background showing certain scenes from Mother 1/EB0, and some from Mother 2/EarthBound.

Site that talks about the magicant stage:
Magicant - Smashpedia, the Super Smash Bros. wiki.