agreed. yoshi is of also undetermined gender.
Trophy specifically refers to it as him or her.
Look again. The subject of the sentence is "foe" making "him or her" refer to the foe, not Yoshi. Yoshi does not swallow himself. Yoshi is male.
Console Representation is mislabeled, it lists console debuts, NOT console representation. If you want actual console representation, then you should list the characters under EACH console they appear on. Otherwise, it's a birthday list. And non-Nintendo as well judging by Snake and Sonic.
Jigglypuff is no more ambiguous than Squirtle, Ivysaur, or Charizard. As is Pichu, Mewtwo, and Lucario. Additionally, Smash refers to all of them as "it." Only Pikachu has a visible difference between Male and Female.
Sheik, at least in Brawl, is referred to as "she."
Ice Climbers is one character, not Popo and Nana separately.
Kirby is not a hammer fighter. Not with one move.
Likewise, there are no bow users; they appear in only one move on each character.
Ness and Lucas should be classified under supernatural powers.
Random Crap and Modern Weaponry could be condensed to Weapon Arsenal. Mega Man may be included too.
Game & Watch could technically be action games.
You included Wario Land AND Warioware: shouldn't it be just Warioware?
You could include more "Neutral" roles. R.O.B., Ice Climbers, and Mr. Game & Watch could be included.