Goombeetle

Astro Goombas are a sub-species of Goombas that are only found in Super Mario Galaxy. They are basically regular Goombas that wear protective helmets, which prevent them from being stomped on.

Super Mario Galaxy
To defeat them, Mario must use a Spin to flip them over and then Jump on top of them. However if they touch Mario, they are still just as deadly as their Goomba origins and will make him lose at least one portion of health (if he does not fall into a Black Hole).

Super Mario Galaxy 2
The Astro Goombas reappear in Super Mario Galaxy 2. Its appearance is similar to the previous game, only now his eyes are bright and are larger than before.

Appearance
Astro Goombas greatly differ from other Goomba subspecies and from Goombas themselves in other ways than the fact that they wear protective helmets on top of their heads. More differences include their eyes which are not white like most other Goomba's eyes but are instead yellow-colored and just visible in the darkness of the helmet. Most Goombas also have a set of pointed fangs in their mouths but since the mouths of these Goombas are impossible to see due to the darkness, it is only assumed that they do not have those trademark fangs.

Trivia

 * The Helmets of Astro Goombas resemble Bony Beetle carapaces.
 * The eyes of the Astro Goombas are yellow, instead of the normal white, and they have no pupils.