Phantoon

Phantoon is a Super Metroid boss found in the Wrecked Ship. It is a supernatural ghost-entity that is intangible and invulnerable except for its single eye. It is this eye that, when open, serves as its connection to the material world and can be damaged. The creature governs over all the Coverns haunting the ship.

Over 4 meters tall, Phantoon resembles a giant squid with a single eye inside a large toothy mouth.

The manual calls Phantoon the ghost of the Wrecked Ship, and states that it is "tapping into Mother Brain's vicious brainwaves." It is possible that Phantoon is controlled to an extent by Mother Brain, or that it is simply borrowing power from her. The fact that Phantoon is depicted alongside Kraid, Ridley, and Draygon as statues at the entrance to Tourian, may indicate that it is directly affiliated with the Pirates, perhaps being a high-ranked member. After its defeat, the Wrecked Ship gains electric power, and Coverns stop appearing. Strangely, Phantoon seems to share a lot of physical traits with the Powamps from Maridia.

Super Metroid's official guide states that Phantoon is drawing power from the ship's "energy crystals". It supports this statement by noting that the Work Robots, which run on internal power, have also shut down "as a result of Phantoon's gluttony".

Super Metroid manual
"THE WRECKED SHIP HAS BEEN SHUT DOWN BY THE FLOATING GHOST, PHANTOON."''

"The ghost of the ship taps in to the vicious brainwaves of the Mother Brain and attacks adventurers with deadly plasma."

Battle
Shortly after Samus enters his room, Phantoon will appear in an intangible ghost form, with a semi-transparent quality to its appearance. While in this semi-transparent form, Phantoon will be completely invulnerable to attack. This form is only engaged while its eye is closed.

As its only basic attack, Phantoon will shed blue-hot "tears" of fire/plasma from its closed eye. These lightly bounce from the floor and walls, and can be destroyed for energy and ammunition. Phantoon demonstrates the ability to manipulate these tears in many ways, including the ability to link large numbers of these into nearly inescapable chains of fireballs. To damage Phantoon, it is necessary to strike it while its eye is opened. Once opened, the body will become solid and visibly opaque. To slow Samus' attack, a large ring of fireballs will form around Phantoon's vulnerable body. If Phantoon is not struck within a very short timeframe once its eye opens, it will disappear for a moment and begin shedding blue tears in his semi-transparent form; it will appear once again rather abruptly, with its eye still vulnerable to attack. Using different weapons to damage Phantoon can cause varying forms of reacting behavior. Using Missiles or the Charge Beam with the Ice Beam enabled will cause Phantoon to disappear and begin to shed blue tears; he is completely invisible to the naked eye at this stage. He reappears after a few seconds. Using Super Missiles is effective, but this will cause Phantoon to position itself at the center of the ceiling and launch long curved chains of fireballs which are extremely difficult to dodge. Samus can however either move in Morph Ball to one side after the first fireball swing passes then to the left (and vice versa) or she can also use the Spin Jump Attack to pass through the fireballs unfazed. If Samus uses the Charge Beam without the Ice Beam enabled Phantoon does not disappear, but he continues to move erratically around the room as if his eye were closed. Several charged shots can hit him, making this the safest and most effective method for causing damage. Eerily, Phantoon will keep his eye centered on Samus as he moves.

Throughout the battle, Phantoon's coloring will gradually change from a dark green to a very hot red-orange, according to how much damage has been inflicted. Once defeated, Phantoon will center its eye upon Samus, begin to self destruct, and then violently dissipate into the air. This will power the Wrecked Ship, and allow Samus to explore it in more depth.

Metroid: Other M
Phantoon appears as the final boss in the game and is fought in the Bottle Ship Control Room during the post game after the credits. Much larger than before, it appears outside the windows and fights telepathically and by breaking through the glass (which has no initial effect other than allowing its attacks to enter the ship due to the Gravity Suit). It retains its plasma "tear" attack, and also attacks with tentacles, an eye laser, energy spheres and vortexes on the ground that draw Samus in and then explode. Phantoon can summon small hand-like organisms with tentacles resembling Reaper Vines, and can send his eyeball into the main chamber of the room to attack Samus directly. Strangely it does not use its known ability to dissipate from the local dimension like in Super Metroid so Phantoon can be damaged by shooting the eye at any time, as the Wave Beam can harm it even if it's outside the ship. Once enough damage has been dealt, it drops down and its eye rests on the floor, vulnerable to a Lethal Strike. When it dies, Phantoon will float out of the ship before exploding.

It is implied that Phantoon leads the special forces unit at this point, as bioweapons are summoned in other sections of the Bottle Ship with the same black hole effect it uses to call the hand-like minions.

Trivia

 * Phantoon bears a resemblance to a boss of the Legend of Zelda game, Phantom Hourglass: Bellum. Most notably, both creatures have an eye surrounded by teeth.
 * He can be seen while invisible with the X-Ray scope, but cannot be damaged.
 * Metroid: Other M's concept art depicts Phantoon as the head atop a vaporous humanoid body, with two larger Rage Hands as its hands.
 * Metroid: Other M has made Phantoon one of the largest bosses Samus has encountered.