Myōga

is a flea yōkai who is a servant to Inuyasha, giving him information on current events, foes, and the shards of the Shikon no Tama.

History
Assigned to protect Tessaiga's hiding place in the grave of Inuyasha's father, he runs away when Sesshōmaru comes there in search of the sword. Myōga often flees before or during a battle, which the others recognize as a sign of pending danger; his mere presence in any area is enough to determine its safety. Myōga enjoys drinking yōkai blood, and actually saves Inuyasha's life at one point by drinking a spider yōkai's venom out of his blood. He can save the others in a similar manner, but often gets squished for drinking their blood without permission. Myōga usually leaves the group regularly to search the land for useful information, and often shows up again at unexpected moments. He is also good friends with Tōtōsai, and often spends time with him when he is not with Inuyasha's group. In the anime series, he is engaged to another flea yōkai named Shōga, but continually runs from her to avoid the marriage. In the series finale, Myōga chooses to remain living with Tōtōsai.

Relationships
Myōga faithfully served the Great Dog Demon for many years, serving as the voice of reason towards reckless actions. Myōga knows of almost all his secrets and the stories of the mighty battles he fought in. It appeared he had no problem with Myōga drinking his blood, which the flea demon said was delicious. Following his death, Myōga was brought to tears. Myōga has known Inuyasha since the half-demon's birth, always addressing him as "Lord Inuyasha" as a sign of respect. However, Myōga has the habit of trying to suck his blood when they meet, only to be squashed. Just like with the Great Dog Demon, Myōga will often try to reason with Inuyasha, to keep him from performing reckless actions. Inuyasha tolerates Myōga for the advice he can give, but is constantly annoyed by his habit of running way from danger. Myoga is sort of a counterpart to Inuyasha of what Jaken  is to Sesshomaru- a knowledgeable and diminutive (in Myoga's case microscopic) servant who is devoted to his master, but constantly ill-treated. However, in Myoga's case at least some of it is deserved because he is much less loyal than Jaken (as he is a complete coward), although he does not suffer Jaken's constant death-threats from Sesshomaru. Myōga is an old acquaintance of the swordsmith, often being found hiding out from danger in the volcano the demon calls home. Tōtōsai often makes fun of Myōga for running away, but it seems both have a good bond of friendship between them. After the three year time skip at the end of the series, Tōtōsai continues to allow Myōga to live with him.
 * Inu no Taishō
 * Inuyasha
 * Tōtōsai

Trivia

 * Ironically, Myōga's means divine protection but as soon as he senses danger, he flees which has been witnessed throughout the series
 * Myōga has arthritis.
 * Myōga used to be a companion of Inuyasha's father, the Inu no Taishō
 * Myōga is the only yōkai in the series so far to have regular human-shaped ears while other yōkais have pointy ones.
 * Myōga often gives vital information, but flees usually immediately afterwards most likely far away from the battle.
 * Having been a faithful companion of Inuyasha and Sesshōmaru's father for many years and already appearing to be rather aged at that time, Myōga is one of the oldest characters in the series.
 * Myoga seems capable of jumping extreamly high as shown in episode 53 when he reaches Miroku up in the air on Kirara.