So here is the answer to the fascinating question that has boggled the minds of millions for centuries. Who is Myoga??  The truth to this question is simple.  Myoga is a flea.  Want more?  Myoga made his first appearance in Episode 5:  Aristocratic Assassin, Sesshomaru and his first order of business was to flee from Sesshomaru.  In the beginning of the show, Kaede is the gang's source of information, but as time goes on and they begin to travel far from Kaede, Myoga takes her place as the all-knowing elder in the group, though he is wrong a great deal more often than Kaede.  Myoga is very old, and presumably was assigned to Inuyasha when Inuyasha was a child by Inuyasha and Sesshomaru's father more than fifty years ago.  He is supposed to be Inuyasha's servant, but his loyalty only extends to how dangerous the situation is.  In other words, when the going gets rough, Myoga gets going.  He also has a habit of revealing information Inuyasha does not want anyone to know.  For example, he knows about Inuyasha's mother, but he's not allowed to tell anyone.  Also, Myoga is frequently hurt.  Inuyasha squashes him flat as a pancake everytime he says something Inuyasha doesn't want him to.  He also gets stomped on whenever Inuyasha gets annoyed.  Kagome has also inadvertantly hurt him several times, running over him with her bike and spraying him with bug-spray are two such examples.  Very little is actually known about Myoga's background, though he has many friends throughout the world because he's always leaving to get information.