Arachnus' room

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

Description
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 more box-shaped layout. 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. Once killed, the Arachnus reveals the Spring Ball that it stole 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.

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 goo and air vents.

Inhabitants

 * 1 Arachnus

Items

 * Spring Ball

Metroid: Samus Returns Official Guide

 * WALKTHROUGH AREA 2 (pg. 65)
 * "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..."