Phantom

The Phantom is a reoccurring character in The Legend of Zelda series, having first appeared in Phantom Hourglass, and returning in its sequel, Spirit Tracks.

Phantom Hourglass
In Phantom Hourglass, the Phantom is enemy that stalks Link around the Temple of the Ocean King. It is similar in shape to a Darknut, but it is able to steal Sand of Hours from Link when it hits him, in addition to normal damage. It is invincible to all weapons barring the Phantom Sword, though it can be stunned by attacking it's exposed back side - it is actually possible to defeat one by continuously stunning it in order to push it into a pit. Phantoms follow preset paths, though if they detect Link they will relentlessly track him down. The Phantom is able to track Link by sound or sight, though it cannot enter or see into "Safe Zones"; if Link escapes into one, the Phantom will forget he is even there, and will leave. Because they follow sound, they can also be tricked into following Bombs or Bombchu. Certain Phantoms are also able to pick up Small Keys and Force Gems, thus requiring Link to slay them to obtain the treasure. The Phantoms are also playable within Phantom Hourglass's multiplayer Battle Mode. Here, players will take turn playing offense (Link) and defense (Phantoms), in a game of trying to collect Force Gems. After the Ghost Ship is cleared, it is revealed that Phantoms are emanations of Bellum created to protect itself as well as obtain more Force.

Types of Phantoms

 * Phantom: The least dangerous Phantom, which wears blue armor.
 * Swift Phantom: A red-armored Phantom which can run faster than Link, as well as pick up dropped items. It also wears a slightly different helmet. It first appears after the Ghost Ship dungeon is complete, and replaces several normal Phantoms.
 * Gold Phantom: A gold-armored Phantom which initially moves slowly, but can teleport to follow Link if he is spotted by a Phantom or Phantom Eye. It wields an axe, unlike other Phantoms.
 * Phantom Trio: Three Phantoms that only appear in the multiplayer Battle Mode. They are basically a normal Phantom in gray armor, though they can pick up power-ups to activate obstacles on the field or empower themselves. However, they cannot pick up Force Gems. They can always see Link (with the exception of when he is in a safe zone).

Spirit Tracks
In Spirit Tracks, Princess Zelda is murdered by Chancellor Cole, who plans to use Zelda's body to release the Demon King. Zelda's spirit is unable to return to her physical state, and thus helps Link on his quest by taking control of a Phantom. This allows offensive backup for Link, as well as helping him solve many puzzles throughout the game.

Phantoms appear in most areas within temples, but in order for Zelda to take control of one, three Tears of Light in the area must be collected beforehand. Link is then required to strike the back of the Phantom with his sword, allowing the princess to take control.

Theory
The final boss of Phantom Hourglass resembles a giant Phantom after Bellum possesses Linebeck. This suggests that the bodies of the Phantoms are separate beings possessed by Bellum, as each Phantom has an eye on its back. The phantoms in Spirit Tracks lack eyes on their back and were good before they were corrupted, but Zelda can possess them. It is possible that phantom only refers to the eye, as it was stated that the phantoms are Bellums alter egos. The bodies may simply be Darknuts.

Trivia

 * Phantoms bear striking resemblance to Darknuts from both The Wind Waker and The Minish Cap.