Yoshi's story actually has a reason you play more then 1 Yoshi.

[JaredThaJa888]

Unlike the original Yoshi's Island, where it contributes nothing more then you looking slightly different each level.

Yoshi's Island DS which I've been playing lately is the same, which disappoints me slightly, besides the different Babies it so far feels like just a "Yoshi's Island" the Lost Levels". I'm also disappointed the White Shy Guys aren't back.

I feel like with both Yoshi and Toad allot of recent games have lost the individual characters by those names for emphasizing them as a species.

[DarkZero]

I do like the multi-colored Yoshi's in YS. Not only does it add some interesting diversity for fruit consumption, but it also makes for an interesting extra-lives concept.

Also, watching your Yoshi get captured is scary when you're a kid.

[Romplayer]

In Super Mario Galaxy 2, Yoshi's color changes if he gets special features. Though it's just for the short time of the effect taking place, you see Nintendo still uses this. But most games just wouldn't profit from different Yoshis, so they don't include it there.

And Toad... well, Toad never was special anyway. Since the first SMB game he always was the same.

[JaredThaJa888]

Since SMB 2 there has been a Character Toad in addition to a race of Toads. IN RPG the individual Toad is repeatedly distinguished. Evne there are about 8 other Toads played by the same or identical Sprites.

Having an individual with the same name as his "Race" isn't as absurd as you might think, a Jew named Judah shares a name with his Tribe.

Yoshi's Island plot wise involves 8 Yoshi's, thought they don't do anything different or special.