Bronze Wraith

The Bronze Wraith is a gelatinous, metallic being found in Pikmin Eco II as the final boss of the main game. While first fought in the Formidable Oak, it gets fought again after it crashes Acorn's ship into the Lone Island. Much like the Oozore, the Bronze Wraith's body is made up of a liquified metallic substance (in this case, bronze), with a small golden orb making up the core of the body, floating inside a ring. It also has a four limb-like "roots" for locomotion, and a small stem for the main body.

Strategy
Unlike other bosses in the game, the Bronze Wraith has two notable boss fights: one taking place within the Formidable Oak, and one on the Lone Island at the end of the game:

Formidable Oak
Inside the Wraith's Den, the Bronze Wraith's attacks vary on numerous elemental attacks against the player, each of which seem to be summoned by the golden orb on its body. Amongst these attacks includes; a fire ball being launched at the player, creating a small spot of flames for a bit; a water bomb that explodes into a small wave on impact; and an electrical bolt of lightning that kills non-electric Pikmin on impact (a ring is seen on the ground where this will strike prior to this attack). The orb itself changes color depending on the attacks it uses, which makes that Pikmin type the only one capable of latching onto it and attacking. throwing the wrong type will make them bounce off.

Lone Island
The final fight against the Bronze Wraith is mainly the same as the one held in Formidable Oak for the most part - similar attacks with similar strategies. However, it gains a few more elemental abilities to use against the player; a spore-like cloud that suffocates any type of Pikmin within its range; an eroding aura wave that immediately buries Pikmin into the ground; A ring of sound that shoves Pikmin into the coastal waters of the island. The method to attack it is still the same, but only when it uses elemental attacks matching your Pikmin (yellow, blue, and/or red).