Sourced name.png
"No matches found in flora and fauna databank"

The subject of this article is not named in-game.
The current title is from a guide or other published source.

For its room in Metroid Fusion, see "Arachnus' chamber".

Arachnus' room[1] is a room in Metroid II: Return of Samus and Metroid: Samus Returns.


Arachnus' room is found inside the Chozo ruins of Area 2. In Return of Samus, it appears similar to other item rooms, but with a unique layout that is more box-shaped. In Samus Returns, its background has been visually updated with high-tech structures, flooding water, a staircase, and a pair of large water wheel-like machines that no longer seem to function properly.

When Samus enters Arachnus' room through a Red Hatch, she finds what appears to be a Chozo Statue holding an Item Sphere. However, the sphere soon reveals itself to be the Arachnus, and a boss battle ensues. In Samus Returns, the Arachnus destroys the Chozo Statue, with its fragments remaining on the floor; this also destroys the statue's raised platform, giving the floor a flattened layout for the boss fight. Once killed, the Arachnus reveals the Spring Ball that it had stolen from the Chozo Statue.

In Return of Samus, Samus can easily exit Arachnus' room through the same doorway that she entered. However, in Samus Returns, the door becomes a Metal Door that cannot be opened from inside Arachnus' room; she can only exit by bombing a Bomb Block in the bottom right corner, revealing a passage that will make use of her new Spring Ball.

In Samus Returns, after the Spring Ball is obtained, Samus can return to Arachnus' room to find it inhabited by Drivels.

Connecting rooms[]

In Return of Samus, a Red Hatch connects to a simple corridor in the Phase 3 Chozo ruins. In Samus Returns, that corridor is integrated into the large dome-like cavern in Area 2, and a Bomb Block connects to a Morph Ball maze of yellow goo and fans.


Return of Samus[]

Samus Returns[]


Spring Ball
The Spring Ball is dropped by Arachnus upon its death. In Return of Samus, it can appear anywhere in the room, depending on where Arachnus died; in Samus Returns, it always appears in the same location, since Arachnus' death animation is a scripted cutscene.

Official data[]

Metroid: Samus Returns Official Guide[]

"A Chozo Statue holding an Item Sphere is waiting on the left side of the room. Shoot it and claim your prize. That Item Sphere looks a little strange..."


  • Arachnus' room is the first room in the entire Metroid series to feature both a boss and a major item, therefore acting as both a boss room and an item room. This would become standardized in later games, such as Metroid Fusion and the Metroid Prime series.
  • In Return of Samus, Arachnus' room is the only room inside any Chozo ruins that is inhabited by a non-Metroid creature. All other rooms only feature robotic enemies or Metroids.
  • Of the three non-Metroid boss rooms in Samus Returns, Arachnus' room is the only one that becomes repopulated with common enemies after the boss is defeated.



  1. ^ Metroid: Samus Returns Official Guide pg. 68: "Roll and jump your way up to the next room and head through the door to reach the area just before Arachnus' room."