Popo Heli

Popo Heli, known as Bobo Heli (ボーボーヘリ) in Japan, is a shielded flying flamethrower enemy from Mega Man 9 that appears in Magma Man's stage and the Special Stage. It is vulnerable at the back, but its face shield can only be penetrated by the Laser Trident, making it easier to defeat them. Unfortunately, it is particularly hard to destroy, as they appear from the top of the screen, come over to the player, and dump fire. They often do this while the player is on a narrow platform, making it even harder to hit. However, they do only require one hit to be vanquished, even from the Mega Buster.

Etymology
Japanese former name probably comes from the word "bōbō" itself, Japanese onomatopoeia of burning sound.