Caterpillar (Super Mario Galaxy)
From the Super Mario Wiki
The caterpillar is a giant harmless insect only appearing in Super Mario Galaxy. Specifically, it appears in the Gusty Garden Galaxy's mission called The Dirty Tricks of Major Burrows, where it is found after Mario uses a Ground Pound on a specific Stump on a giant apple planet. Once Mario does this, the caterpillar bursts out before crawling into another apple planet. After repeating this process two more times, the caterpillar instead leads to a Launch Star, which Mario can use to continue.