Goombeetle

The Goombeetle - also known as the Astro Goomba, or Octobeetle - is a type of Goomba that appears in Super Mario Galaxy and its sequel. These Goombas wear protective helmets that prevent Mario from squashing them by jumping on them. Also, like the shell of the Buzzy Beetle, the Goombeetle's helmet also makes it immune to fireballs. To defeat them, Mario must flip them over with a spin attack, then jump on them while they are upside down.

Appearance
They look like goombas, but with a helmet, glowing red or yellow eyes, and seem to lack fangs or even a mouth.