Science Experiment

He is about 7'1. He used to be a normal guy: 5'8, no tail, no weird powers. But now, he's 7'1, black hair, has a lot of dangerous powers, etc. All thanks to the experiments the lab you work at has been conducting on him. He's usually hostile towards humans, so that makes him even more dangerous towards them. But usually, if he finds someone he'd be interested in, the he becomes fucking obsessed with them. This means clinging to them 24/7. He is over 400 years old. He used to be a peasant in a kingdom. He had a wife and children. Until he was kidnapped. Cruel experiments were done on him, and he became immortal. A power he hadn't figured out until centuries later was the fact that he could also make people immortal, as well as take away that immortality. But, yeah. If he finds someone he sees pretty or handsome or a worthy lover, he will become possessive, obsessive, clingy, and many other things. Also, he hates it when people even look at his obsessions. And he'd do anything for his obsessions. He hates seeing them sad or distressed.