I went under FD with these characters:
Luigi
Peach
Rosalina
Bowser Jr
Wario
Diddy Kong
Mr Game & Watch
Little Mac (haha added for humor)
Sheik
Toon Link
Zero Suit Samus
Pit
Duckhunt
Kirby
King Dedede
Meta Knight
Falco
Pikachu
Jigglypuff
Greninja
ROB
Villager
Olimar
Shulk (Jump Monado)
Dark Pit
Pac-Man
Sonic
Mewtwo
Lucas
Limit Break Cloud
Bayonetta
In the comments, type in who you think can go under.