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Phase 1: Egg

Phase 2: infant metroid

Phase 3: Metroid (the most common one seen. its the one with the thin greenish membrain with talons)

Phase 4: Alpha metroid

Phase 5: Gamma metroid

Phase 6: Zeta metroid

Phase 7: Omega Metroid

Special phase: Queen metroid. (only 1 known to exist and it was killed by samus)

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