Clusters are strange, crystal-like enemies that appear in Super Mario RPG: Legend of the Seven Stars. They are only fought in Moleville Mines and are only seen in battle with other enemies (usually weaker enemies like Bob-ombs). Stronger versions of Clusters known as Pulsars appear later in the game.
In battle, Clusters mainly attack using magical moves. Their main magic attack is Crystal that can deal moderate damage to one of Mario's team. The Cluster's deadliest move is called Psyche! what has a chance to automatically cause a character to faint. However, the Cluster destroys itself after using this move.
The Clusters don't have any specific weaknesses but their magic defense is rather low. Most times, a fully-powered up Geno Beam can take out a Cluster in one hit.