From the Super Mario Wiki
Retrieved from "https://www.mariowiki.com/index.php?title=Bocci_Ball&oldid=2637779"
Bocci Balls are objects that appear in Yoshi's Story. They only appear in Blargg's Boiler and Piranha Grove, where they are partially submerged in lava, and placed above Piranha Stalks that will hurt the Yoshis if they touch them. They are named after the sport of bocce, which involves rolling balls around. The Yoshis use them to traverse the lava or stalks by balancing on it and rolling it forward.