Shadow Link
Shadow Link (also know as Dark Link) appears several times in "The Legend of Zelda Series."
Shadow Link has the ability to copycat and utilize Link's every move, but each Shadow Link has his own advantages in each game.
Zelda II: The Adventure of Link
In this game, Shadow Link is the final boss of the game. This Shadow Link is literally, Link's shadow! Before the battle begins, the lights in the room go out, you see Link's shadow jump away from him, and the duel among yourself starts. After you defeat Shadow Link you proceed to awaken Princess Zelda.
He is not considered to be one of Ganon's minions, but many believe he is the final test put on Link by the King of Hyrule himself.
Ocarina of Time
This Shadow Link serves as the mini-boss in the Water Temple as an adult. He has the ability to stop you from slicing him, leaving you frozen for about 3 seconds. If you fail to attack, he will fall through the ground, and reappear behind you, and try to slice you from the back. Once you have defeated him, you receive the Longshot.
Oracle of Ages
Shadow Link has a larger role in this game, as he is the main antagonist and final boss. At the second stage of the boss battle, Vernan summons 4 Shadow Links, and they are extremely weaker than Link. They serve merely as distractions, and can be defeated easily.
Four Swords Adventures
In this game, Shadow Link is not just an enemy, but a repeated boss. There are many Shadow Links that are constantly being created by the stolen Dark Mirror, and while these copies go around causing trouble, Link is accused of all of their doings. Shadow Link will show himself twice per stage, and is the boss for the Cave of No Return, Village of the Blue Maiden, The Dark Cloud, and the Desert Temple stages. His last appearance is in the Desert Temple when Princess Zelda finally manages to un-do the seal on the Dark Mirror, causing it to cease creating Shadow Links.
Twilight Princess
While being told a story by the Light Spririt Lanayru, you see three Dark Links who appear to crush Link. There's nothing significant about this, they just act as visual tools to intensify the tale. These Shadow Links do not appear in this game as enemies.
Spirit Tracks
In Castle Town, at the "Take 'em all on" mini-game challenge, Shadow Link is the final enemy Link must defeat in order to win. He has the ability to use the Great Spin attack, Bombs, and the Bow, while Link only has his sword. Like most of his predecessors as you begin to defeat him, he slowly becomes more and more transparent.