Atarunians are a race of aliens from the 13th Planet in the Kokeru Solar System that are shown in the Keroro Gunso Franchise.
Atarunians are known to have tremendous amounts of bad luck that can only be countered by a stone known as the Good Luck stone, which can only be found on Atarunian and are worth a lot. Atarunians usually have an aura of bad luck around them, and seem to be unfazed by their bad luck. Rei Kinoshita is the only Atarunian shown in the series, and she appears to have even worse luck than normal Atarunians.
Atarunians appear to have the ability to erase memories, and stop time, and when they have there Good Luck Stone they can teleport.
Atarunians grow very much like Pekoponians, looking almost human like except for the ever growing aura of bad luck. When Atarunians are little they are given the Good Luck Stone, and possible live on their own. (As Rei is shown alone at a very young age.)