Toxic Bulblax

The Toxic Bulblax is a boss enemy very similar to the original Emperor Bulblax in the first Pikmin game, but with a different coloration. The invincible backside is purple instead of green, and the fungi that grows on it glows neon colors. Its face is deathly white and it has disturbing red eyes. The tongue is black instead of purple. As the name implies, this boss possesses the same attacks that Emperor Bulbax did in the first Pikmin game (as well as his roaring attack from Pikmin 2) and poison gas also flows through cracks in the rock that makes up its back, shrouding the area around the boss in poison. It also has the ability to spew a large cloud of poison gas out of its mouth. The boss is very difficult to fight without white Pikmin, and with white Pikmin you'll be able to get in plenty of hits while it tries to use poison gas against you. HOWEVER: you also run at the risk of dragging out the fight if you aren't careful. Whenever the boss eats white Pikmin, the poison actually energizes it and restores its life instead of poisoning it and damaging it! The stakes are high with this boss, which is encountered in the Ancient Wetland, on the ninth and final floor of the Dead Man's Trench. Portal- Kombat

In other Games
In Pikmin: Wrath of Mr.B

In Pikmin: Wrath of Mr. B the toxic bulborb is the boss of several caves and one of the hardest enemies in the game. The fight is nearly identical to in PTAY, except for that the creature's tongue is highly adhesive and all pikmin except black ones will be stuck and eaten in great numbers. Note that toxic bulbaxes cannot summon mitites. Also note that one of the reasons that makes this boss so hard is it's extraordinary amount of health, double that of the Emperor Bulblax!