Baoh

From the same creator of JoJo's Bizarre Adventure, teenager Ikuro Hashizawa can transform into the parasitical bio-weapon, Baoh, gaining superhuman strength and other abilities such as firing a corrosive substance. He escapes from the Secret Organization Dress along with a young psychic girl, Sumire, and the two must face various assassins sent by the organization to kill him.

Link:
JoJo's Bizarre Encyclopedia (Manga)
AnimeNewsNetwork (OVA)