Hookshot

HookShot is an item featured in some of the Legend of Zelda games by  Nintendo. The most common form enables Link to fire the hook at an object (pots, rocks, etc) or an enemy. If fired at an enemy, it will just act as a long range attack weapon, but is not as effective as the Bow and Arrow. If it hits an object, it will pull Link towards the object, even if there is a gap in the way.

A Link to the Past
This item made its debut in The Legend of Zelda: A Link to the Past. Link finds the hookshot in the Flooded Palace. While Link shoots it, he is invincible, and cannot be harmed. It is used to stun enemies, but mainly to pull Link across gaps. It hooks on the wooden items (tees, treasure chests, etc.)

Link's Awakening
The hookshot is found in Catfish Maw, and is used to beat the boss, Slime Eel. When you enter the room to fight the mini-boss (Master Stalfos), he flees, and you do not receive the hook shot. When you go out, you will find a note say he found the "special item" that was there. Chase him down (he travels around a few different rooms) to finally beat him to gain the hookshot. It is used the same way, and is needed in order to learn the Frog's Song of Soul.

Ocarina of Time
For the first time, the plane is 3D, so you can now shoot the hook shot up in order to get to higher grounds. It won't hook to all woods; mainly on wooden bulls-eyes. It is obtained once you beat or at least nearly match Dampe in a race, and is needed to enter the Forest Temple. For the first time, the hookshot gets an upgrade, known as the Longshot. The longshot is twice as long as the original hookshot. It is used to get to the boss of the Water Temple, and in order to beat its boss. When you get captured by Gerudos, the hookshot is needed in order to get out of their jail.

Majora's Mask
The hookshot is located in Gerudo Lagoon. The Gerudo are talking with one another, with the hook shot in the room. Have Link shoot an arrow at the bee hive above them to scare them out. Go around and get the hookshot. It is need to get the Zora egg in the tank.

Oracle of Ages
Whilst Oracle of Ages didn't actually feature a Hookshot, it featured a very similar item, the Switch Hook (and, later, the long hook). This still gives the ability to travel across gaps, but differs in the fact that, rather than being pulled towards the object, you switch places with it. This allowed for some interesting new puzzles for the game. You also switch places with enemies, rather than attacking them.

Wind Waker
The hookshot makes another appearance in the Wind Waker. This time, it can hook to many different wooden objects. It is used to beat the boss of the Wind Temple, and is needed to get on top of Ganon's Tower.

Super Smash Bros. Series
The hookshot is featured in Super Smash Bros. and  Super Smash Bros. Melee as Link's grab attack. He can also hang off some ceilings (like Samus Aran).