Rex

He was found by a villager as a child during a large battle of two supernatural sides. (No humans were really involved) As a child, Rex was taken to a human village to hopefully have a good chance at life. He looked and acted relatively human along with making sure not to 'show his ears'. After a year or two rumors about the villages cattle getting killed by wolves spread to other neighboring villages. Some people were suspicious of foul supernatural play, however. And set up a little trap for any potential wolves that may be around. Two men caught Rex in a frenzied rage. Half human, half hellhound. He had a hard time controlling his instincts when close to a full moon or low on energy. Discovering this, they sent rex to a military base to see if they could use werewolves as a potential asset to their firepower. Both against humans, and other supernatural beings.