Golden Statues

From Wikitroid, the Metroid wiki

The Golden Statues appear in Super Metroid. Each statue represents the four major bosses in the game before Mother Brain. These bosses include Kraid, Phantoon, Draygon, and Ridley. Ridley rests atop the head of Phantoon, while Kraid and Draygon are to Phantoon's sides.

This statue takes the same role as the statues of Kraid and Ridley in the original Metroid (later just their heads in Metroid Zero Mission), as they both have in common the role of guarding the entrance to Tourian. As Samus defeats the bosses depicted, their corresponding statues will each one-by-one lose their golden glow, and seem to "die." Once all four are defeated, the entire structure will sink to the bottom of the chamber, caving in the floor and revealing the entrance to Tourian, which is underwater.