Jermafenser

Jermafenser, also known as Helmethead,  is the boss of Midoro Palace in. It reappears as the boss of the Palace on the Sea in the original Family Computer Disk System version of that game; in the NES version, it was replaced with Gooma.

In the Famicom Disk System version, Jermafenser only has one floating helmet when fought in Midoro Palace, with the second head only appearing on the Jermafenser in the Palace on the Sea. In the NES version, the Jermafenser that appears in Midoro Palace has the second head. In the NES version, the boss of the Palace on the Sea is Gooma, a creature original to the NES version.

Strategy
Like Mazura, the previous boss, his weak point is his head. Unlike Mazura, he attacks Link by throwing fireballs at him from his head. When Link lands a blow to the head, the helmet will come off and be replaced by another one. The detached helmet will then begin to float around and attempt to kill Link by shooting more fireballs and running into him. When Link knocks off two helmets, his true head will rise from the armor - a white head (seemingly with one eye). For the rest of the battle, Link fights the boss while also dodging the fireballs shot by the helmets. After achieving victory in the fight, Link returns one of the Crystals to the palace.

Non-Canon Appearances
Jermafenser makes a brief appearance in Captain N: The Game Master during the episode entitled Having a Ball. At the end of the episode, Jermafenser stands tall behind the throne at King Hippo and Eggplant Wizard's party in the tower, fanning King Hippo, while Moblins play music in the background. When Link, Kevin and Princess Lana retrieve the Triforce pieces from Eggplant Wizard and King Hippo and use all three against them, Jermafenser is destroyed along with the Moblins.