In Super Mario World, we introduced to Yoshi, a rideable companion of the Mario brothers, available in various colours. While green Yoshi can only spit out the shells it ate, other coloured Yoshi’s gain special abilities when consuming shells. Red Yoshi’s spit out fireballs instead of the shell, blue Yoshi’s gain the ability to fly while having the shell in its mouth and yellow Yoshi’s can stomp the ground to create sand clouds which defeats enemies, also while having a shell in its mouth.

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Um actually … Green Yoshi’s (and all Yoshi’s in general) are able to obtain all the abilities above, but they need to eat shells of that colour.