red yoshi:red yoshi is found on star road 1 and 4. he starts off as a baby. feed him and he grows into cavalry "somethin u can ride" when he eats a koopa troopa shell (any brand)
he can spit out fire, three large fireballs 1 up 1 down and 1 center. (i dont recon this guy too much)

yellow yoshi:he is found in star road 3 and 6. he starts off as a baby . feed him and he
grows into cavalry( you know what it is) when he eats a koopa troopa sheel (any kind)
he can do a sand stomp some to the left, some to the right ( this guy is good against spikey's,
koopa's etc)

blue yoshi: he is found only in star road 2 . he starts off as a baby. feed this fella and he
grows into cavalry(duhhhh huh huh huh...)when he eats a koopa troopa shell (any kind)
he can grow wings and fly better than the caped dude ( this is defenetly my favorite character! the wings are so handy. and you can find him w/ yoshi in cheese bridge or bowser land 3 and find wing's)

note: you have to feed a yoshi 5 enemy's or one powerup so it will grow so you can ride it.