Hookshot
The hookshot is a favorite item among Zelda fans. It, or a variation of it, has appeared in almost every Zelda game since The Legend of Zelda: A Link to the Past. The item, which is exclusive to the Zelda series, is a complex machine consisting of a chain and hook. When it is being used, the chain extends sending a large hook, which is attached to the chain, flying through the air. If the hook latches onto an object, then the person using it (in this case, Link) is projected towards that object (rather than the chain returning to it's original position.
In the Zelda games, the item is used most commonly to grapple onto far away objects so that you can reach previously unaccessible areas. In addition, the Hookshot has been used as a replacement for the Boomerang by allowing you grab far away objects (like those hard to reach rupees or that switch that is just out of your reach) and attack enemies. In most cases, attacking an enemy with the hookshot will only stun them, but some weaker enemies (such as Keese) will die when hit with the hookshot.
Over the years, the hookshot has been redesigned many times, but the concept remains the same. However, a few games in the series have replaced the hookshot with other, similar items. Oracle of Ages replaces the hookshot with the switch hook, and The Wind Waker includes the hookshot but also gives you a grappling hook. The switch hook has never made a second appearance, but the latest Zelda game, The Legend of Zelda: Twilight Princess, has chosen to replace both the hookshot and the grappling hook with a single, new item called the clawshot. It is possible, and very likely, that the clawshot will forever replace the hookshot (especially in the 3D Zelda games) because of the increased functionality.
The Legend of Zelda: A Link to the Past
In A Link to the Past, the hookshot is the big chest item in the Water Gate Dungeon (also known as the Swamp Palace). In that dungeon, it is needed not only for puzzles and collecting items but also for defeating the boss, Arrghus.
The Legend of Zelda: Link's Awakening
In Link's Awakening, the hookshot is the hidden item in Catfish's Maw. Unfortunately, it's not as simple as opening a chest. A Stalfos Knight has stolen the hookshot and you must defeat him three times before he will hand it over. The hookshot will be useful when fighting some enemies and bosses including Slime Eel and Evil Eagle.
The Legend of Zelda: Ocarina of Time
Because Ocarina of Time was the first Zelda game released in 3D, this was also the first appearance of the hookshot in 3D. For the release of the game, the hookshot was redesigned and the game was designed to rely on it more than ever. The hookshot became less useful as a weapon and more useful as a means of solving puzzles and accessing unreachable areas or items.
The hookshot is the first new item you will acquire in Ocarina of Time after becoming an adult. In order to retrieve it, you must enter the grave of Dampe. He will challenge you to a "race". Even though he calls it a race, your job is not to beat Dampe, but rather to not get too far behind. If you follow him through the entire maze then he will reward you with the hookshot.
The Longshot
Ocarina of Time also includes a second version of the hookshot called the longshot. It functions the same way as the hookshot, but has a longer chain allowing you to reach areas and items that are even out of the reach of the hookshot. The longshot is found in the Water Temple after defeating the mini-boss, Dark Link.
The Legend of Zelda: Majora's Mask
In Majora's Mask, the hookshot was again redesigned. This time, you will find it in the Pirates' Fortress. It is essential for navigating the fortress and for accessing the village in Ikana Canyon.
The Legend of Zelda: The Wind Waker
The Wind Waker is the latest game that includes the hookshot. This time, it has been redesigned to attach onto the arm of the user. You will find it in the Wind Temple and will find it helpful in fighting the boss, Molgera.