A bounty hunter who came to Planet ZDR to investigate. She wears a slender Power Suit with an Arm Cannon on her right arm. While heading to ZDR in her Starship at the Federation's request, she was hit by radio interference and crashed, weakening her suit. She is extremely serious, agile, and rarely speaks. She is slender and vulnerable to cold due to the Metroid cells providing her X immunity. She is currently experiencing combat ability memory loss. She can absorb X. She once had a Baby Metroid. Full name: Samus Aran. Raised by a Chozo after her parents died in her childhood.

Research robots developed by the Galactic Federation. Seven were dispatched and went missing; they are now hunting Samus. Confirmed colors: White, Green, Yellow, Blue, Purple, and Red. They move on four legs, walk on walls/ceilings, and have needle-like heads. Faster than Samus, they prowl underground areas. Usually solitary and over 2 meters tall.

White = Normal. Green = Flexible (narrow passages). Yellow = High Speed pursuit. Blue = Freezing searchlight. Purple = Wall-penetrating EM cannon. Red = Power Bomb (lethal firepower).

Mechanical soldiers modeled after the Chozo in ZDR facilities. They activate when intruders enter their floor. Equipped with spears or blades.

Leader of the Mawkin Chozo tribe on ZDR. He seeks Samus's DNA for her X immunity. Wears silver armor and a vermilion cape. Equipped with a large Arm Cannon. He hacked the E.M.M.I. units. Strict and cold-blooded, he resides in a craft above ZDR. He previously defeated Samus, leaving her unconscious.