Ground Urchin

Ground Urchins are enemies in Super Mario Galaxy and Super Mario Galaxy 2. Ground Urchins look and act much like normal Urchins, except they are red and appear to be covered in some sort of fuzz, unlike the solid skin of normal Urchins. When defeated by fire, they burn into black chalk before disintegrating into dust.

Super Mario Galaxy
In Super Mario Galaxy, Ground Urchins appear in the Freezeflame Galaxy, where they are found in the lava area and act as the primary enemy. The player can defeat them by either shooting them with fireballs or luring them into the lava. One also appears in the mission Boo in a Box of the Deep Dark Galaxy.

Super Mario Galaxy 2
Ground Urchins reappear in Super Mario Galaxy 2, where they are named Hot Urchins. They behave exactly like how they did previously. They are found on only a single planet in the Battle Belt Galaxy.

Super Mario Galaxy

 * Trading Card description: Urchins are spiky blue fish that Mario must face in an underwater challenge in the Beach Bowl Galaxy and a land mission in the Freezeflame Galaxy. They roll along the seafloor or ground trying to poke Mario with their spikes. There are also red Urchins in lava areas that Mario can hit with a fireball or trick into falling into the lava.