Barney Bubble

A Barney Bubble is a round purple creature that spits out bubbles when stepped on in Super Mario World 2: Yoshi's Island. There's two in the game, and they only appear in the Monkey's Favorite Lake level. Grabbing their bubbles with the tongue lets Yoshi spit out more bubbles. Also, in Yoshi's Island: Super Mario Advance 3, there are two more added in the World 6 Secret, Endless World of Yoshis.

Trivia

 * Its name is a pun on Barney Rubble of The Flintstones.