After Samus defeated the Metroid Prime on Tallon IV by absorbing Phazon and using it as a weapon against Metroid Prime, the creature began to destabilize, and in a desperate move, it absorbed her Phazon Suit and subsequently exploded. As Samus left the planet, a new creature was born from Samus' DNA and the remains of Metroid Prime, using Samus' Phazon Suit as a mold to contain its new body - the creature known as Dark Samus.