Morpha

Giant Aquatic Amoeba: Morpha (水棲核細胞モーファ, Aquatic Cell Nucleus: Mōfa) is the Boss of the Water Temple in Ocarina of Time. Probably created by Ganondorf once he acquired the power of the Triforce, it has complete control over the water in the room in which it resides, moving swiftly through it and creating long water "limbs". This monster is responsible for the state of Lake Hylia as well as the frozen condition of Zora's Domain.

Strategy
This creature may seem to be a fearsome tentacle made of water, but in all actually it is only a bouncing red ball. This ball is Morpha itself. The advantage it has is that it can manipulate the water in any way it likes, creating one (and eventually two) large water tentacles. These tentacles try to grab Link, squeeze him, and toss him toward the spikes surrounding the arena. It is the best idea to try to avoid the tentacles when they lunge forward and focus on the core. When a tentacle lunges forward, use the Longshot to grapple the core and pull it towards you. Once it is right in front of you, use the Master Sword and slash it. (If you can, try to keep the core on dry land and keep slashing it. Or better yet, trap it in a corner and completely ruin its day.)

Keep repeating this process. It will eventually summon a second tentacle, but this is not that much of a big deal as long as you avoid it. Just keep focusing on the tentacle with the core in it. When Morpha is defeated, the core will burst in a spray of water. The tentacle will cling to life as long as it can, using up all the water in the central pool. Once it uses up all the water, it will drop to the floor and splatter.


 * THE QUICKEST SPEED KILL, GUARANTEED!***

The Master sword works fine, but if you are lucky enough to already have the Biggie sword from delivering the EYE medicine to BigBrother on the Mountain top, then you are ready for swifter speed kills on most enemies, including the mighty Morpha! Pssh! Please. {You can search how to get the Biggie sword on almost any "Ocarina of Time" walkthrough}

Upon entering Morpha's Boss chamber, jump down into the pit straight foward and then climb up the nearest ladder to the entrance way. This beast will show itself. Now, jump back onto the entrance cliff and turn around to get Morpha's attention. As it approaches you, head to the corner to the RIGHT of the entrance way [YOU at the entrance way, facing the large room, go right.]

Now, Use "Z" targeting on the nucleus of Morpha and just back straight into the corner as far back it allows you to go. Directly face this Aquatic Monster and DO NOT let go the "Z" targeting, or you will have to get another "Z" targeting lock on the nucleus BALL inside Morpha's gel-like worm-water form. Use the "LONGSHOT" to yank that meatball out of Morpha's gutz! LOL.

"Z" targeting is critical. Keep using the longshot on it over and over, as you keep pulling the BALL out to strike it down! You must either use the Master sword or Biggie Sword to kill Morpha's nucleus ball, which then destroys Morpha. Simple! Hey, You didn't expect it to be this easy, but kids gotta play this game too, so this makes it easier for kids to deal with this BOSS, just incase you were wondering why there are "cheats" and tricks for the game.

If Morpha acts stubborn, just run towards it, until it starts to go after you. When the second water worm comes out, be careful not to get caught by its grip, or you will go flying like a wack superhero! Hahaha. The safest spot is the entrance way. Why?? because the spikes are a good distance away from Link. Work your way back into the right corner and destroy Morpha with ease once you get close enough for a "Z" target love affair :) NO, you can not be touched by either water tentacle, so don't run out. Never let go "Z" once you lock it down.

It's just TOO EAZY to kill this thing in this corner. Good Luck!

Link's rewards for this victory is a Heart Container and the Water Medallion.

Trivia

 * Bear in mind that this battle CAN be completed with the Hookshot as opposed to the Longshot.
 * Din's Fire is capable of evaporating Morpha's tentacles, a useful trick in a bind.
 * Morpheel is a reference to Morpha both in the way its first stage is defeated and in name.