Ache

The Ache are enemies appearing in The Adventure of Link. They are blue or purple bats related to the Keese, although they are more resilient in combat, harder to destroy, and have magical abilities.

Called "Eyes of Ganon" by townsfolk, Ache can disguise themselves in the villages of Hyrule as ordinary Hylians, but are most often found in caves and trees. They can be killed with bladed weapons such as a sword.

The Acheman is a close relative to the Ache.

Animated series
An Ache makes a brief appearance in "The Ringer" episode of the Zelda animated series. Like the rest of Ganon's minion, the Ache is capable of speech. When Ganon arrives disguised to the Magician's Contest being held in North Castle, he makes a bird turn into an Ache and orders it to go see who is guarding the Triforce of Wisdom. The Ache then flies off to the tower where the Triforce and Link are located and sees that Link and Spryte are next to the sacred relic. The flying foe then returns to Ganon and informs him that the young hero is guarding the Triforce.