List of creatures in Metroid: Zero Mission

This is a list of creatures that appear in Metroid: Zero Mission'.

Acid Worm
A long, tentacle-like creature that appears in Kraid's Lair after activating the ziplines. It appears from a shallow pool of acid and attacks by shoving its entire upper body out of the acid, while leaving some of itself still submerged to serve as an anchor. Samus must wait for it to wiggle its tentacles (the sign it will attack) and ride the zipline in the room to another platform. The worm gets stuck in the block Samus was standing on, exposing a weak exoskeletal joint that is highly vulnerable to Missiles. However, damage can be dealt via Beams.

Bio Barrier
The Bio Barrier is a living blockade- a large smooth sphere suspended in the air by veinlike appendages. It will not attack players and cannot be defeated by any of Samus' weapons. The only way to destroy it is to carry the small parasites, called Blootiks, who attach to Samus, to it. When she approaches a Bio Barrier with Blootiks on her, they will leap off and quickly eat away at the Barrier. It should be noted that unless Samus has the Varia Suit, these bugs will damage her as well if there are at least four on her.

Blootik
Tiny parasites who attach to Samus if she touches them, but do not do any damage to her unless there are many attached to her at once. The Varia Suit seems to nullify this damage. They disappear if the Morph Ball Bomb is used or if Samus walks to another room. The Blootiks can be used to destroy Bio Barriers by eating them.

Charge Beam Worm
This spiny worm of incredible size appears at different points in the Brinstar region until Samus defeats it or it appears five times. It uses its long body to box in Samus, then shoves its head at her. Upon returning the head to the ceiling, it opens its eye to find Samus. The eye can be damaged during this time. As the name suggests, killing the creature gives Samus the Charge Beam.

Imago
A giant bee-like organism who is originally fought in its cocoon, but is later fought inside a cave to obtain the 'first' Super Missile pack (Super Missiles can be obtained beforehand and thus Imago can be skipped, or, if you DO fight him, you would need only 8 Super Missiles to defeat him)! As a cocoon, the player must use the Winged Ripper to jump up and hit the "vines" holding it up, making it crash through the floor. In its final form, the player must repeatedly hit Imago's stinger to kill it and cause it to destroy another wall and obtain the Super Missiles.

Mecha-Ridley
The final boss of Zero Mission, encountered deep inside the Space Pirate Mothership, is a massive robot that bears a striking resemblance to Ridley. It appears to be incomplete at the time of the battle, as it has no legs, and drags itself around by its arms. It attacks using its razor-sharp claws, lasers, a homing missile launcher, and can send a barrage of fireballs out, similar to the real Ridley. Notably, with the exception of a single panel on its chest, the machine is completely impervious to Samus' attacks. When Mecha-Ridley is destroyed, it, like the Mother Brain before it, triggers a self-destruct sequence within the Mothership.

Ruins Test (also called Warrior Shrine)
When Samus finally works her way through Chozodia and escapes the Space Pirates, she reaches a room that she once visited as a child. This room contains a massive painting of a Chozo warrior. This is not a typical "boss battle" but rather a Chozo-developed test of Samus' abilities. She then engages in battle with this painting; four emblems are present on the surrounding wall, and they are "absorbed" by the orb the warrior is holding. The orb will occasionally flash an emblem, and Samus must shoot the orb with a fully charged pistol shot during this brief period of time. When an emblem is not showing, the orb has a mirror image of Samus. If the orb is shot during this time, Samus damages herself. Passing the test requires shooting all four emblems (they return to their respective location on the wall after being shot once). When this happens, Samus' mirror image shows her wearing the new Power Suit, which she subsequently absorbs. She has thus earned her new Power Suit, and activated the three Unknown Items. In the cut-scene at the end of the game, it is revealed that she chipped a crude engraving of herself and her adoptive family into the painting as a child.

Eye-On
Eye-like creatures which emit a beam of light. If the beam is disrupted, they alert the Space Pirates of Samus' presence and begin shooting energy beams, but they can be destroyed simply by shooting them with the Plasma Beam; however, they are impervious to Samus' Stun Pistol. They can only be found in Chozodia.