Nettori is a large plant-like boss and is the result of the plants from SR388 being infected by the X Parasites. Nettori is the source of the heavy vegetation that extended throughout a large portion of Sector 2 and into a small area of the Main Deck; the vines caused the main power to go offline by choking the components of the Main Reactor. Once Samus restores the auxiliary power, she still has to find out what is causing the main generator to malfunction. After she enters a secret tunnel to a vine-choked Sector 2 and encounters an SA-X, she comes upon Nettori deep within the sector.
When Samus enters the room, she will see some plants that resemble Rafflesia flowers or Venusaur and some small pods or buds growing on vines on the walls; on the right side of the room stands a large biomass that resembles a Torizo or Chozo Statue and is intertwined with vines -- that is Nettori. At this point, it won't have any active role in the battle and is completely open to attack; during the first phase, it relies on its flowers to fight Samus.
The two seemingly unbloomed flowers on the vines above Samus release clumps of pollen at regular intervals, which float down and will damage Samus on contact, knocking her into a water pit covered by one of the larger flowers; the pollen can be shot out of the air, however. The three big flowers on the bottom will remain dormant until Samus falls into them, at which point they will start to drain her energy. If she falls in, panicking and repeatedly jumping won't help; the trick is to make one long jump to get out, since the pits are filled with water.
In the middle of all this, Samus is supposed to damage Nettori's main body. If she stays in the Morph Ball on the platforms, she'll avoid all of the plant's attacks. However, this position doesn't present an advantageous way to attack. An unintentional flaw in the pollen's flight path allows Samus to crouch on the far left side of the raised platform, where she can constantly shoot Ice Missiles into Nettori's main body. The pollen will occasionally block the missiles, but Samus can simply keep firing. A rapid volley of Missiles will make short work of the first form of Nettori. Another way to defeat Nettori is to continuously lay Power Bombs; these will not only damage Nettori, but also destroy any pollen, opening a path for a missile run.
Once Samus does enough damage, the front part of the plant will crumble away, the pods on the vines will disappear, and the Rafflesia-like flowers will begin spewing pollen of their own. In order to avoid this, Samus must stand on the raised platform in the middle of the room.
Nettori will now use the Plasma Beam against Samus. If Samus is crouching, Nettori will shoot low; if Samus is standing or jumping, Nettori will shoot high. Samus can dodge the shots by jumping or crouching accordingly. Once Samus has fired enough Ice Missiles at Nettori, it will transform into a Core-X, trying to ram her and shoot her with its acquired beam weapon (in this case, the Plasma Beam) as they normally do. Samus regains the powerful Plasma Beam upon its defeat.
- Nettori's name may possibly be derived from nettle, a species of poisonous flowering plant found on various continents. It could also be a combination of nettle and Torizo, which the central mass resembles.
- Because of the biomass's resemblance to a Torizo/Chozo Statue, one could assume that the Nettori started off as a simple plant (possibly a creeper vine) and, when it came into contact with the statue's energy-generating capabilities, was mutated and spread throughout the BSL station. This most likely occurred after the statue was infected by the X Parasites as it would explain how the plant-life managed to grow to such an enormous size so quickly and chaotically.
- The plants found between the platforms appear to be Blob Throwers in regard to their appearance and projectiles, though they behave like the Samus Eaters from Super Metroid, in that these trap their prey and do not extend.
- The pods located near the ceiling share many similarities with the pods seen during the battle with the Spore Spawn. One of these similarities is their pattern of attack, which consist solely of spitting out harmful spores/pollen. The two boss' battle themes are also quite similar.
- If Samus exits and re-enters the room where she fought and defeated the Nettori, every plant within will have wilted and acquired a reddish-brown color. This also happens to the Spore Spawn and its room immediately after it dies.
- The Plasma Beam shots fired from Nettori act as a shield, causing any of Samus's weapons to bounce off of them. However, once Samus has obtained the Plasma Beam function, it allows enemy projectiles through.
- Nettori is one of the few bosses that is vulnerable to Power Bomb blasts.
- Strangely enough, when Nettori becomes a Core-X, and even when Nettori is defeated, Samus will not be able to open the door to the right until the Plasma Beam has been obtained, despite the fact that all vegetation has been removed, reactivating the station's power. This is probably to prevent skipping the Plasma Beam.
- On Easy Mode (Japanese version of Metroid Fusion only), the unbloomed flowers remain closed and do not release any spores.
- In the Metroid Prime & Fusion Original Soundtracks, Nettori is referred to as the Fake Statue.
- Nettori's battle is similar to Mother Brain in that both have a single safe place to stand, hazards on the ground and weapons attacking from above to assist them, and before they attack in their second form (Mother Brain's second form from Super Metroid as well as in the battle from Metroid: Zero Mission), they start firing lasers.
- After Nettori's "head" section breaks off, it is noticed that its Plasma Beam's explosion makes a sound effect exactly like the Ice Missile's explosion sound.
- Ferrothorn, a Plant Pokemon, bears certain resemblances to Nettori. Ferrothorn's Japanese name, Nattorei, is spelled similarily, both plants have a semi-inorganic main body, and both have large vines.
- Metroid Fusion: The Official Nintendo Player's Guide refers to Nettori as a "giant root".