Pikachu = Red Bird, but when he disappears, he turns into a shock of lightning that works best on metal.

Raichu = Same as Pikachu, but is heavier and has a stronger shock of lightning.

Jigglypuff = Blue Bird, when tapped, two music notes are sent alongside Jigglypuff.

Mew = White Bird, when tapped, Pikachutwo (http://bulbapedia.bulbagarden.net/wiki/Pikachutwo) will fall out of the sky and hit the structure, then explode.

Mewtwo = Lazer Bird, can go anywhere you want it to.