From the Super Mario Wiki
Star Crusters are creatures in Super Mario RPG: Legend of the Seven Stars. They appear in Bowser's Keep the second time it is visited, alongside much weaker creatures. Star Crusters seem to be a more powerful version of Crusties. Like Crusties, Star Crusters have extremely high physical attack and defense, but low magic stats. In battle, a Star Cruster will only use its normal attack on its own turns; if hit with a normal attack, however, they will immediately counter with a projectile that puts the attacker to Sleep. Though they seem to be crab-like, Star Crusters deny being crabs and seem to be especially offended when labeled as such (this strange quirk may mean that they are actually not related to Crusties, who are assumed to be crabs as they are both crab-like).
Names in Other Languages
|Star Kānī, Kānī being the Japanese name of the Crusties