Boon

Boons are large, quick, rock-dropping fly enemies.

Zelda II: The Adventure of Link
In Zelda II: The Adventure of Link, Boons appear in swamplands and plains in the latter half of the game, as well as on Maze Island. They fly in from the top of the screen and dart around erratically while dropping an endless supply of stones at Link. They can be defeated with a single sword strike, though this is complicated by their movements.

Captain N: The Game Master
In Captain N: The Game Master, Boons appear in the episode "Once Upon a Time Machine," where they fly in to drop rocks upon and steal items from the heroes.

Link: The Faces of Evil / Zelda: The Wand of Gamelon
In both Link: The Faces of Evil and Zelda: The Wand of Gamelon, Boons appear as occasional enemies, appearing at Spearfish Falls and Lupay in the former game and Ahitaru in the latter. Rather than dropping rocks, they fly in a deliberate manner towards the player character in endless amounts, like many other enemies.