The Big Green ChuChu is a Green ChuChu fought while being Minish sized as the boss of the Deepwood Shrine in The Legend of Zelda: The Minish Cap. It is the first boss of the game and the last obstacle between Link and the Earth Element.
The Big Green Chuchu slips its way inside the Deepwood Shrine while Link is inside exploring the dungeon. The Big Green ChuChu is a pretty easy fight. Link must just avoid its pretty slow attacks and use his Gust Jar to suck Chu Jelly from the bottom of the Big Green Chuchu. The Big green ChuChu will then fall over, which makes it open to sword attacks. After repeating this method for a few time, the Big Green ChuChu will die, leaving a Heart Container behind and allowing Link to reach the Earth Element.
The Minish Cap Figurine
"Appears in Deepwood Shrine. A perfectly ordinary Chuchu. Though not much of an enemy usually, they are terrifying to anyone Minish-sized."