Jacob liked his Xbox and games where he could be a warrior. If he could he'd use the name Xenobian. He'd read that once in a science fiction story. Or saw it somewhere. He liked to have a name that started with an X.
He saw himself as slaying long-fanged creatures, mostly with tails and horns like donkeys and devils. But not the good kind, like Hellboy. Instead, he might even sometimes choose to have a tail and horns himself; only he would be much better looking than Hellboy. Not red but maybe blue would be okay.