Goombeetle

Goombeetles (also referred to as metallic Goombas and Octobeetles) are a type of Goomba only found in Super Mario Galaxy and its sequel Super Mario Galaxy 2. They are Goombas that wear protective helmets, which prevent them from being stomped on. They are sometimes described as being robotic Goombas.

Super Mario Galaxy
Goombeetles first appear in Super Mario Galaxy. They are mostly found in Bowser's and Bowser Jr.'s galaxies. They are also found in the Buoy Base Galaxy and the Dreadnought Galaxy. They attack by charging at Mario, just as regular Goombas. However, unlike regular Goombas, they cannot be defeated by being jumped on. To defeat them, Mario must flip them with a Spin and then jump on them. Each one defeated releases a coin. If they are, however, defeated with a Bullet Bill, they will release three Star Bits.

Super Mario Galaxy 2
The Goombeetles reappear in Super Mario Galaxy 2. They act and appear the same way as they did in the previous game. They appear in Bowser Jr.'s Fiery Flotilla, Beat Block Galaxy and Chompworks Galaxy. They can be defeated by the Co-Star Luma or instantly defeated by a Chomp, which like the previous game causes them to release three Star Bits.