Metroid Prime (the creature) was a disgustingly mutated Metroid living in the depths of Tallon IV, and able to produce Phazon. Samus Aran faced it, and it was encased in a black shell. After the shell was defeated, Metroid Prime fell to a lower level, and the horrible, pink, tentacled blob that was the creature itself came out of the shell and fought Samus. Before it died, it stole Samus's phazon suit and exploded. After Samus left the planet, a bubbling pit of phazon was left, and a black claw shot outwards, a claw with an eyeball in it's back. This claw belonged to the new form of Metroid Prime, a form that made heavy appearances in both Metroid Prime 2: Echoes and Metroid Prime 3: Corruption: Dark Samus.