Yellow Shell

Yellow Shells are yellow Koopa Troopa shells found only in Super Mario World. When Yoshi hits the ground after a jump, with a Yellow Shell in his mouth, a shockwave will surround him. This will cause the enemies to flip over or defeating all nearby grounded enemies. Yoshis can also spit it back out, in which case it will behave like a Green Shell does, flying out at high speed and knocking over all enemies in its way. Unlike the other Koopa Troopas though, when a yellow koopa is knocked out of its shell and it gets into any color shell, the shell becomes multicolored, invincible to Mario (but not Yoshi), and and will chase after Mario. If Yoshi were to eat a multicolored shell, he would fly, be heavy, and spit fire all at once.

Like other Koopa Troopa shells, the Yellow Shell will be launched when the Koopa Troopa wearing it is jumped on. It can also be held and thrown. If the player attempted to launch the shell back at the koopa then it would grab and throw it back at the player.