Kraid's room

Kraid's room, also known as Kraid's quarters and Kraid's chamber , is the room where Kraid is battled in his lair.

Metroid
In the original Metroid, Kraid's room is constructed from blue and silver architecture. The ceiling of the room features silver spikes and red orbs, arranged in a manner that resembles the teeth and eyes of a large creature; a similar structure appears in the room just outside his chamber, as well as in Ridley's room.

The room is locked behind a Red Blast Shield. Kraid resides on a platform in the center of the room, with small pools of acid on either side. Unlike any of its later appearances, the layout of this room does not change at all during the boss battle.

Zero Mission
In the remake Metroid: Zero Mission, Kraid's room is found in the same place as the original game, but its design has been thoroughly overhauled. The room is constructed from sand-red blocks, with dark red rock formations in the background. There is no longer acid or any other hazard in this room, not counting Kraid himself.

When Samus Aran first enters the arena, she is able to stand on a number of large blocks on the right side of the chamber, letting her easily jump and shoot at Kraid. Alternatively, she can use the Power Grip to grab onto a block directly above the door, giving her maneuverability to dodge Kraid's attacks. However, as the battle continues, Kraid destroys most of the large blocks with his stomach spikes, making it difficult for Samus to find a position to shoot Kraid's head. When Kraid is defeated, the arena shakes and small rocks fall from the ceiling as Kraid sinks into the floor, suggesting that the room is partially collapsing, which may be an explanation for why Kraid seemingly disappears after the fight.

After Kraid's defeat, the entrance door remains locked, but Samus can now use Bombs to enter a new room to the left of the arena, where the Speed Booster can be acquired. She can then use the Speed Booster to break through the remaining large blocks and exit the chamber through a hidden passage. Alternatively, the door is automatically unlocked upon entering the Speed Booster room, allowing Samus to leave Kraid's room without picking up the item.

Super Metroid
In Super Metroid, with Kraid's Lair being located in a different section of Brinstar, his new quarters are technically a separate room from the one previously featured in Metroid and Zero Mission. As such, it is radically different in appearance; while it has a few blue rocks like those seen in old Brinstar, it is largely overgrown with green vegetation, spiked growths, and thorny vines.

When Samus first enters Kraid's quarters, the chamber appears unoccupied, only for Kraid to appear by burrowing up through the rocks and spikes on the floor. After taking some damage, Kraid will rise up to his full height, breaking through the chamber's ceiling and doubling the room's size. Samus has to climb up his stomach spikes and use midair platforms to reach Kraid's vulnerable head. Upon Kraid's death, the chamber shakes and large rocks fall from the ceiling as Kraid sinks into the floor, much like in Zero Mission. Additionally, the midair platforms crumble and the floor spikes disappear one by one as Kraid sinks down.

With Kraid defeated for good, Samus can enter the adjacent room to the right to gain the Varia Suit.

Inhabitants

 * Kraid

Metroid

 * Energy Tank
 * A single blue block on the right side of the room, just above the acid pool, can be destroyed to reveal an Energy Tank.

Trivia

 * In the April/May 1988 issue of Nintendo Fun Club News, the first place winning entry of the Metroid Art Contest is an illustration by Jeremy Gregory depicting Kraid's room.
 * Metroid is the only game where Kraid's room is not guarded by a Gadora.
 * A Zero Mission pre-release screenshot of Kraid shows him in a very different room, which appears to be a cave partially submerged in acid.
 * In Zero Mission, it is possible to defeat Kraid with Super Missiles before he destroys any of the blocks on the right side of the room. Because the door remains locked, Samus is still required to enter the Speed Booster room to proceed; when Samus returns to this chamber, the blocks will have disappeared as though Kraid had still destroyed them.