From the Super Mario Wiki
Elite Octoombas in Boulder Bowl Galaxy
Elite Octoombas also called Green Octoombas or Fast Octoombas are enemies from Super Mario Galaxy 2. Elite Octoombas resemble their blue cousins, Octoombas, but they are green in color and have two antennae on their heads. Elite Octoombas attack exactly like common Octoombas but since they have two antennae, this means that they shoot two rocks in rapid succession instead of one. They appear in multiple galaxies, namely the Boulder Bowl Galaxy. Just like Octoomba, they give a warning before attacking by turning red and moving their heads back. They are not as resilent as Octoguys but can be quite difficult when there are in vicinity.
Names in other languages
|From Takobō, the Japanese name for Octoomba.
||From Poulba (Octoomba) and bi (two in latin, could come from the two rocks an elite Octoomba shoots)
||From "Oktumba" (Octoomba)
||From "Polipoomb" (Octoomba)