Sky Pop Yoshi
From the Super Mario Wiki
Sky Pop Yoshi is a Whirly Gate transformation in Yoshi's Woolly World and Poochy & Yoshi's Woolly World that appears in the levels Fanciful Fluff and Feathers and Kamek's Last-Ditch Flyby. It is based off of the Sky Pop from Super Mario Land.
In this form, Yoshi has the ability to fly. He can also shoot missiles at enemies to defeat them if the player presses . However, like all other forms, this form has a time limit, and Yoshi must collect all of the available clocks and make it to the ring at the end.