Parasyte

Parasyte is a Japanese manga series written and illustrated by Hitoshi Iwaaki. It was published in Kodansha's seinen manga magazines Morning Open Zōkan (1989) and Monthly Afternoon. The manga was published in North America first by Tokyopop, then Del Rey, and finally Kodansha USA. The series follows Shinichi Izumi, a high school senior who is the victim of a failed attempt by a parasitic organism to take over his brain. The parasite, Migi, instead infects and takes over his arm, and both are forced in a peculiar partnership to fight other parasites.