The main character (the blond ponytailed guy - yeah, guy) is Aramiya Satoshi, who main ability is shapeshifting into any animal ...though at a few points he has plants growing out of him, so my guess is he can shapeshift into any living thing (including an elephant and a lion) I'm not sure if he was naturally born that way or if he was a biological experiment. Anyway, he's a pretty easygoing guy who just wants to be left alone to enjoy his solitary life in the middle of a junkyard, but apparently some army or another is always after him because of his ability, though he is able to fight off entire tank battalions before breakfast.
(Source: Mangahelpers)