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The current title is from a guide or other published source.

The giant root's arena[1] is a room in Sector 2 (TRO). It appears in Metroid Fusion.


This room is found in the middle of Sector 2, but only becomes accessible midway through the game. It contains Nettori, an X Parasite-infected plant that becomes the source of vegetation choking the Central Reactor Core. The room is infested with vines, which cover the ceiling and walls. More vines extend into the background, as well as tall green plant stalks with pustules. Below the entrance is a pair of Pit Blocks, which drop Samus into the chamber itself. Three Samus Eaters exist in pools of water at the bottom of the room, with two platforms, one of which is slightly raised. Two Samus Eater Buds exist on the ceiling and constantly spit spores, although on Easy Mode (Japanese version only) they are closed for the entire battle. Behind the boss itself is an open area, which is filled with more vines and two more pustule-covered stalks. Nettori is encased in vines, which break once Samus destroys the creature and it reverts to its Core-X form. Small red flowers can be seen growing from those vines.


Samus confronts Nettori's Core-X.

When Samus enters the room, the door behind her locks, despite the fact that she could not get back to it anyway, due to the Pit Blocks. She drops through the Pit Blocks into a Samus Eater and must escape immediately. Once she does, Samus is able to attack Nettori. She must do so while avoiding the Eater Buds. Once Nettori reverts to its Core-X form, Samus can go behind where it was and finish the boss off. Absorbing the Core-X restores her Plasma Beam ability, and allows Samus to leave. The door remains locked until the Core-X is absorbed, likely to prevent her from skipping the ability. Nettori's defeat kills the vegetation strangling the Central Reactor Core, restoring power to the BSL station.

If Samus returns to the room following the battle, the foliage will have decayed and turned a light brown color. The Samus Eaters and Buds are gone, leaving behind empty pools of water. This can be observed by exiting and immediately returning to the room after recovering the Plasma Beam.

Connecting rooms[]

Samus enters this room through a large corridor in the tropical section of TRO. It exits into a curving shaft leading back into said corridor.



Plasma Beam
Defeat Nettori.

Official data[]

Metroid Fusion: The Official Nintendo Player's Guide[]

4. BOSS BATTLE (pg. 79)
"Hanging plants fire projectiles that aim to knock you into adventurer-eating flowers in the giant root's arena. Clear away the projectiles with Wide Beam shots or Power Bomb blasts and hit the root with as many Missiles as you can muster. After you severely damage the root, it will fire lasers. Jump or duck to avoid the shots and continue to hit the root with Missiles. If you fall into the flowers, jump as high as you can to get out of them."
"Fire at the projectiles from the hanging plants with your Wide Beam or blast them with a Power Bomb."
"After the giant root takes a lot of damage, it will begin to fire lasers high and low. Eventually, it will take the form of a giant Core-X. Defeat it for the Plasma Beam."

Metroid Prime and Metroid Fusion: Prima's Official Strategy Guide[]

Page 124
"Go through the door to face a giant plant boss that is responsible for fouling up the Reactor Core. When you drop into the room, Samus falls into plants on the floor. Climb up to the pillar as quickly as possible, because the plants will try to hold Samus down. Meanwhile, the spore shooters on the ceiling fire spores at Samus, trying to knock her off the pillar. If you respond quickly to each impact, directing Samus back to the pillar, you can maintain your attack against the massive plant to the right. Continue firing Ice Missiles at the giant plant while avoiding the spore shooters. Eventually, the front of the plant falls away, and it begins shooting triple beams at Samus. Jump to avoid the beams and continue firing at the boss.
It takes a bushel of missiles to defeat the giant plant, so be patient. If you run out of missiles, use Charge Beams, but be especially careful to avoid its beams while you charge up for the next shot. Your persistent attack finally destroys it, releasing a Core-X. This is a beam Core-X that shoots back, so you must continue jumping back and forth over the Core-X as you aim missiles at the eye. When your attack destroys the Core-X, jump and grab the green X to regain Samus's Plasma Beam ability. Now, Samus's beam attack penetrates enemies, damaging multiple targets."
Tip (pg. 124)
"The giant plant shoots high and low, so you must jump or crouch accordingly to avoid being hit."