From the Super Mario Wiki
In Super Mario World 2: Yoshi's Island, the Official Guide from Nintendo Power describes how the Yoshi franchise has different enemy classes. Of those, one of them is Projectilia Ritebakatchia, a pseudo-scientific name corruption of "projectile" and the phrase "right back at ya." Enemies in the class Projectilia Ritebakatchia throw projectiles at a Yoshi. They can usually be defeated by normal means, but sometimes they cannot be eaten. Common examples of these enemies include Wild Ptooie Piranhas, Blow Hards, Ukikis with watermelons, and Lakitus.