Parasite
Parasite, 寄生獸
arasyte (寄生獣 Kiseijū, "Parasitic Beasts") is a manga series written and illustrated by Hitoshi Iwaaki, and published in Kodansha's Afternoon magazine from 1990 to 1995.
Parasyte centers on a teenage boy named Shinichi Izumi. He lives with his mother and father in a rather quiet neighborhood when, one night, an alien invasion occurs. The aliens are called Parasites. They are worm-like creatures that enter human "hosts" through their ears or noses, and take over their brains. A Parasite attempts to crawl into Shinichi's ear and take over his brain while he sleeps, but is stopped by his headphones and accidentally burrows into one of his hands instead. In the Japanese version, it takes over his right hand and it is named Migi (ミギー).
(Wikipedia: The Free Encyclopedia, s.v. "Parasite")
