Doomknocker

Doomknockers are a type of armored enemy wielding a spiked club.

Zelda II: The Adventure of Link
In Zelda II: The Adventure of Link, Doomknockers are a heavily armored type of Gūma in most later palaces, starting with the Island Palace. Like normal Gūma, they move back and forth over a small area while facing Link and occasionally jumping. Unlike them, however, they wield maces that they throw in a rapid straight line forward, which after a substantial distance reverse direction, returning like a boomerang. Sometimes they may jump over a returning mace, causing it to continue in the other direction. Potentially due to their armor, they also have more health than a normal Gūma.

In the Japanese version of the Maze Island Palace, the final stretch before the boss chamber features a Doomknocker in a teal color, matching the palace's walls in that version. However, it still is the same coded object; the blue palette is often given the wall colors in rooms with falling blocks, which that particular room lacks. This Doomknocker is removed in western releases.

Captain N: The Game Master
In Captain N: The Game Master, a Doomknocker appears in the Island Palace in the episode "Quest for the Potion of Power." Its armor is beige, its club is wooden, and both are seemingly covered in outward-facing screws.