Tosenbo

Tōsenbo are spiked, slug-like creatures found in outer space. They are exclusive to the second stage of the Space Zone in Super Mario Land 2: 6 Golden Coins. These creatures inflate and deflate at a regular interval, but are barely visible when they are not inflated. They are invulnerable when not inflated, so Mario should stay away from them; they can only be defeated using a Star or a Fireball when they are in their inflated state.