his in a room on the ceiling
in the main room
kill the lakebed temple boss or collect enough heart pieces
If you want to find the BOSS for the Lakebed Temple on Twilight Princess, you have to get the BIG KEY and then go to the room with the giant swiveling staircase, and just jump into the water. The BOSS DOOR is level with the water surface under the swiveling staircase. This BOSS is the coolest one so far. -Caveman1593
The Frog Toad is the miniboss of the Lakebed Temple. After defeating it, you get the Clawshot, which is the dungeon item.
For the first part, use the clawshoot to pull Morpheel's eye out. For the second part, chase after him and use the clawshhot to pull yourself to his eye and attack it.
It's on the map.
beat the boss
in the main room
Look on the map
You finish off the forest temple mini boss
The mirror of twilight is in the desert. you gain access through the mirror of twilight after defeating the boss of the desert temple.
You get it in the sky temple when you beat the mini boss.