Big Octo

The Big Octo, sometimes spelled Bigocto, is an enemy that resembles a giant Octorok, appearing as a mini-boss in and  and as a regular enemy in.

Ocarina of Time
In Ocarina of Time, the Big Octo has made its home in the insides of Jabu-Jabu's Belly. When Link arrives at its lair, he throws Princess Ruto up on top of a platform to get the Spiritual Stone of Water. Upon grabbing it, however, Princess Ruto is taken up to the next room by the platform. Then the platform sinks, revealing the Big Octo in its entirety. The Big Octo is none other than a large, mutated Octorok.

The weapon of choice for this battle is the Boomerang. The Big Octo circles around the middle and chases after Link. Link in effect, must do the same thing- circle around until he reaches the Big Octo. Link should hit it with his Boomerang, forcing it to turn around and become stunned for a moment. Its only weak spot is on its back, so Link must run around the circle and try to hit its back before it starts to run again. For this reason, Link has to stun it from a fairly decent distance in order to have time to get around and stun it again while it is facing the other direction. With a jump slash with the Deku Stick, the Big Octo is killable in one hit.

Another strategy to defeat it prolongs the battle, but it is a good way to ensure not being hit. Link can hit the creature with his Boomerang to stun it; then, when the creature spins around, Link can throw the Boomerang at it again to stun it again (Link needs to target the mini-boss in order to do this effectively). In most cases, Link manages to stun it when it turns its weak spot to him. Other times, it turns its face to him.

A third strategy requires losing one heart of health, but is by far the easiest and fastest way to kill the creature. If Link walks into the Big Octo (each time costs half a heart), then it shakes, and turns around and heads the other way. If Link is quick enough, he can throw the boomerang at the Big Octo, hitting it from behind and stun it, then attack its weak spot with a jump slash, doing double damage. Doing this twice kills the Big Octo.

Majora's Mask
The Big Octo also appears in the swamps of Termina in  Majora's Mask, guarding the way to the Deku Palace and the Deku Shrine. There are three of them in total, and they are far easier to kill than in Ocarina of Time, a single shot from the bow is sufficient (in fact, it's possible that an arrow can kill the Ocarina of Time Big Octo instantly as well, except the item is obtained long after the creature is killed). However, the first time around, Link must ram into them with the boat. They also automatically die after completion of Woodfall Temple. They do little in Majora's Mask except for blocking passage to the palace, or sucking Link towards them and spitting him away if he comes too close.

The Wind Waker
In The Wind Waker, Big Octos are large squid-like creatures that inhabit the waters of the Great Sea and will appear if Link sails nearby. Their locations are marked on the Sea Chart after getting the Octo Chart. One has 4 eyes, three have 8 eyes, and two have 12 eyes. To defeat one, Link must shoot and destroy all of its eyes.

Each one appears in a whirlpool, which can be seen with by the large number of Seagulls flocking around it, this acts as the initial challenge to killing a Giant Octo. As the Octo surfaces, the whirlpool pulls Link and the King of Red Lions into its mouth. If all of its eyes are not destroyed before reaching the center of the whirlpool, the Big Octo sucks Link up and spit him out, sending him out to the edge of the quadrant.