Phantom Ganon (Ocarina of Time)
When Link first enters the boss chamber, it appears as if he is confronted by Ganondorf himself. However, the man pulls off his mask, revealing himself to be a creation of Ganondorf, Phantom Ganon.
After Link defeats Phantom Ganon, Ganondorf will acknowledge the impressive feat, but also comment that Phantom Ganon is just a shadow of Ganondorf's true power, stating that the real battle will be much more challenging. Ganondorf then banishes Phantom Ganon to the gap between dimensions.
Phantom Ganon serves as Link's first major challenge as a boss as his attacks do considerably more damage than any boss Link has encountered at this point. There are six paintings around the room and it will appear as if two phantoms are galloping out of the paintings. At the last moment, one of these becomes an illusion and will turn around, while the actual Phantom Ganon will jump into the battlefield and zap lightning around the room, which will deal two whole hearts of damage. It's a good idea to stay against one of the corners, as the lightening attack won't quite reach Link from there.
The goal here is to use your Bow or Hookshot and hit Phantom Ganon, right when he is coming out of the painting. Doing so will deal damage, causing him to run back into the painting. Never standing in the center of the room, and instead, stand against one of the sides, allowing you to see more paintings at one time. If possible, you want to stand so that you can see both paintings with Phantom Ganon at once, so you can see which is the real one and quickly react to it. After three successful hits with your Bow, Phantom Ganon will lose his horse and come out into the main room.
For the second phase of this battle, Phantom Ganon will float around the room and shoot less powerful orbs at you. These attacks will do a full heart of damage if they hit Link. While they're easily avoided or blocked with your shield, you'll actually need to use them in order to harm Phantom Ganon. Just before the orb is about to hit Link, target Phantom Ganon and swing your sword, causing the orb to shoot back out at Phantom Ganon. He may volley the orb back at you and you have to continuously volley with Phantom Ganon until the orb hits him. He will come crashing to the floor, allowing you to run up and deliver multiple sword slashes.
Very rarely, Phantom Ganon will power up and charge directly at you. You can block this attack with your shield, or simply move out of the way. Be careful as this attack does three full hearts of damage if it connects! After a number of hits, Phantom Ganon will be defeated.