Bonkotsu Shinpei no Monster Life@COMIC

The protagonist is an ordinary soldier from an empire at war who gets used as a guinea pig for genetic engineering experiments, turned into a monster and put into cryosleep.
Two hundred years later, he wakes up in a world of swords and sorcery. The empire is gone and he has to survive alone in the body of a monster whom everybody wants to kill on sight. Meanwhile, he encounters various pretty ladies (and elves) in need of rescue.