From the Super Mario Wiki
Octoguys also known as Octoomba Leaders are recurring enemies in Super Mario Galaxy and Super Mario Galaxy 2. They look like regular Octoombas. They are just like Octoombas in the game because they can spit rocks upwards. But the main difference between them is that, Octoguys shoot rocks faster, and can chase Mario.
Super Mario Galaxy
In Super Mario Galaxy, they are semi-common enemies appearing in mass numbers in the Honeyhive Galaxy, Buoy Base Galaxy, Gold Leaf Galaxy, and Deep Dark Galaxy. In the Honeyhive Galaxy, they appear in the water-filled planet, trying to prevent Bee Mario from getting to the Queen Bee. They also appear on the Queen Bee's planet. Two of them appear on the fortress in the Buoy Base Galaxy. In the Gold Leaf Galaxy, they appear in the final planet of the second mission in the water-filled section. In the Deep Dark Galaxy, they guard a Fire Flower that is needed for Mario or Luigi to proceed through the level. A lone Octoguy also appears in "Bubble Blastoff", trying to knock Mario off a pole he is climbing.
Super Mario Galaxy 2
In Super Mario Galaxy 2, Octoguys return. They appear in the Boulder Bowl Galaxy, in the Honeyhop Galaxy and Shiverburn Galaxy's Prankster Comet mission.
Names in other languages
||From Poulba (Octoomba) and maybe obus (shell,missile)
- ^ Super Mario Galaxy 2 Official Prima Games eGuide, page 26.