Bubble
From Starfy Wiki
There are two types of bubbles - small, and big. Small bubbles are found in Gluglug Lagoon, and within them can be two things: nothing, or pearls. They can be popped by using a Star Spin. Big bubbles can be found in the Sogwood Forest and on Planet Bunnera. In Sogwood Forest, big bubbles fall from the sky by the use of giant acorns. On Planet Bunnera, however, they do not need a giant acorn, or anything else to trigger them - they just float around. This is a good thing, as if they don't go anywhere, then it's easier for the player to get where they want to be.