Silver Zebesians are a variety of Zebesian encountered in Super Metroid. These powerful Space Pirates dwell in Zebes, guarding passage to Ridley's room. They are found in Lower Norfair, appearing in one room. There are two of them which must be killed to continue. Their front is invulnerable, while their back is capable of being harmed. Silver Zebesians are the strongest forms of Zebesians found on Zebes. Their behavior and battle technique is almost identical to that of the Gold Zebesian appearing in Metroid Fusion.