Big Green ChuChu
After entering the boss room, a short cutscene will take place. In the cutscene, Link will see a ChuChu appear and hop towards the shrine and enter it. After the cutscene, Link will see balls of jelly fall to the ground and dissolve. The frequency of the jelly balls will start out slow, speed up, and slow down again. After the last jelly ball has dissolved, the gigantic ChuChu will fall into the room.
The battle begins with the ChuChu slowly moving towards Link. It may also jump high in the air and try to land on him. Link can avoid the ChuChu and use the Gust Jar to suck up its foot. Once enough of the foot has been sucked up, the ChuChu will sway back and forth in large movements while trying to follow Link until, finally, it falls over. It will always fall over towards the side Link is standing on. Once it has fallen down, Link can slash at its head. Eventually, the ChuChu will stand upright again and regrow its foot.
Link will need to repeat the same process at least two more times to defeat the ChuChu. After enough damage has been caused to it, the ChuChu will begin jumping much more frequently. This will not, however, affect the battle process. After slashing the ChuChu enough, it will begin to explode. After a bunch of small explosions, the ChuChu will explode into a cartoony puff.
After a few seconds, the Earth Element will float down into Link's hands. A Heart Container and a warp tile will be left behind. Link can grab the Heart Container and head through the warp tile to go back to the dungeon entrance.