Mimisenri

was a demon who had very good hearing, and told Naraku the location of the final shard of the Shikon no Tama.

History
When Naraku appeared before Mimisenri, the large eared demon asked if Naraku planed to absorb him into his body so that he could hear things extraordinarily well too, but Naraku replied he had no interest in absorbing a filthy body such as his. Mimisenri heard Naraku coming from "four miles away" and asks if he's seeking information on the Shikon shards, hearing from numerous demons that Naraku had gathered most of them. Naraku corrected him and said there is only one shard left he could notfind, so Mimsenri strained his ears, listeed for rumors on the jewel, and told Naraku that the final shard is in the Borderland between this world and the afterlife.

Powers & Abilities
Mimisenri had the ability to hear everything that happened in the world, even under water, and possessed great wisdom because of this.

Trivia

 * For some reason in the English dub of the Anime in the very first episode, he appeared in Episode 127: Don't Boil it! The Terrifying Dried up Demon with his first debut on screen with Naraku and spoke to him. Naraku addressed him with the wrong name and called him "Mimisendi" instead of the correct "Mimisenri". It is possible that it is less correct by saying "Mimisendi", but it is hard to tell in that particular part of the speech.
 * For some strange reason, Mimisenri appears along with Naraku and his minions in the opening "One Day, One Dream", despite only having a minor connection to him.
 * Mimisneri's name and his ability resembles to two character from the Chinese mythology; his name is the combination of  (adapted from 順風耳 ', "With the wind ear") and (adapted from 千里眼 ', "Thousand miles eye"), his ability is the same as the Shunfeng Er.

Mimisenri Mimisenri 顺风耳