Giant Ghost Pikmin
The Giant Ghost Pikmin is an optional boss in Pikmin 3: The Progg Wars. It only appears if at least 100 Pikmin die before entering its room, and is thus impossible to defeat on a zero death run. It oozes ectoplasm, which is what its attacks are based on.
It will fire an ectoplasmic laser, ectoplasmic bullets, and it will slam the ground creating an ectoplasmic shockwave.
How to defeat
Throw pikmin at it. They will bounce off of it, but they will still hurt it. You need exactly 100 throws to defeat it.