His parents were human and goat hybrid, but a creeper genetic came up in his family a long, long time ago. He just happen to get the creeper genetic his 3x great grandfather carried. 

When he was young he didn't know how to control his creeper abilities (I don't know what else to call them) So on the first day of school he saw a human child and blew up (from fear maybe) so they rushed him to hospital. They had to amputate his right arm as well as do surgery on his chest and left eye. This led to him having cybernetics implanted. 

Don't touch his bush