Mario: Dr. Mario
Luigi: Mysterious Mr. L
Peach: Sunshine Dress
Bowser: Dry Bowser
Donkey Kong: DK Jr. Shirt
Diddy Kong: Sunglasses from DKC2
Link: Ordon Village Clothes
Zelda: Link to the Past Dress
Sheik: Ocarina of Time Suit
Ganondorf: Wind Waker Robe (same hair)
Toon Link: Outset Clothes
Yoshi: Bow on head (Yoshi doesn't change colors with this costume, the bow does)
Samus: Fusion Suit
Zero Suit Samus: Casual Clothes (End scene Metroid Zero Mission)
Pikachu: Female tail
Jigglypuff: Bows return as their own color set
Pokemon Trainer: Ranger Uniform
Squirtle: Mystery Dungeon Scarf
Ivysaur: Mystery Dungeon Scarf
Charizard: Mystery Dungeon Scarf
Lucario: Mystery Dungeon Scarf
Kirby: Beam Kirby Hat (features Marx colors, disappears when copied another character)
Meta Knight: Maskless
King Dedede: Iron Mask Dedede
Fox: James McCloud glasses
Falco: Assault Uniform
Wolf: 64 Clothes
Captain Falcon: Classic Falcon
Ness: Pajamas
Lucas: Pig Mask
Ice Climbers: Hoodless
Marth:
Ike:
Mr. Game & Watch: Helmet
Pit: Armored
Wario: Overalls Wario
Olimar: Helmetless
ROB: With Stack-Ups to the sides and behind
EDIT: Ninspriter, Ton directly said that these costumes don't become anyone else. And I agree. They are just costumes and shouldn't change the character in any way.
Luigi: Mysterious Mr. L
Peach: Sunshine Dress
Bowser: Dry Bowser
Donkey Kong: DK Jr. Shirt
Diddy Kong: Sunglasses from DKC2
Link: Ordon Village Clothes
Zelda: Link to the Past Dress
Sheik: Ocarina of Time Suit
Ganondorf: Wind Waker Robe (same hair)
Toon Link: Outset Clothes
Yoshi: Bow on head (Yoshi doesn't change colors with this costume, the bow does)
Samus: Fusion Suit
Zero Suit Samus: Casual Clothes (End scene Metroid Zero Mission)
Pikachu: Female tail
Jigglypuff: Bows return as their own color set
Pokemon Trainer: Ranger Uniform
Squirtle: Mystery Dungeon Scarf
Ivysaur: Mystery Dungeon Scarf
Charizard: Mystery Dungeon Scarf
Lucario: Mystery Dungeon Scarf
Kirby: Beam Kirby Hat (features Marx colors, disappears when copied another character)
Meta Knight: Maskless
King Dedede: Iron Mask Dedede
Fox: James McCloud glasses
Falco: Assault Uniform
Wolf: 64 Clothes
Captain Falcon: Classic Falcon
Ness: Pajamas
Lucas: Pig Mask
Ice Climbers: Hoodless
Marth:
Ike:
Mr. Game & Watch: Helmet
Pit: Armored
Wario: Overalls Wario
Olimar: Helmetless
ROB: With Stack-Ups to the sides and behind
EDIT: Ninspriter, Ton directly said that these costumes don't become anyone else. And I agree. They are just costumes and shouldn't change the character in any way.