Ache

From Zelda Wiki.org

Ache
Game(s)	Adventure of Link
Habitat(s)	Villages
Effective Weapons	Sword

Be careful, you never may know that the "Eyes of Ganon" are watching you until it's too late to react. The Ache (エーク, Eiku) are blue and purple bats that are related to the Keese, although more resilient in combat, harder to destroy, and that have magical abilities. They can disguise themselves in the villages of Hyrule as an ordinary Hylian and attack anyone that attempts to trifle with their spying for the Evil King. They can be killed with bladed weapons such as a sword. They made their appearance in Adventure of Link.

The Acheman is a close relative to the Ache.