Ball Yoshi did not originate from fanon, and the information on this page may not be entirely accurate to their canon. You may read more about this subject in the context of their canon on the following wiki(s):
“Destroy Everything! The ball's invincible! Don't panic as you tilt the Game Boy Advance with each bounce.”
— Yoshi Topsy-Turvy
Ball Yoshi is one of the forms Yoshi can transform into in Yoshi Topsy-Turvy. In this form, Yoshi transforms into a round, bouncy ball. He is invilcible in this state, and is able to roll into enemies and walls to destroy them. Ball Yoshi is entierly controlled by tilting the Game Boy Advance, with him moving as the ground shifts.