subhuman       
adjective  disapproving uk/ˌsʌbˈhjuː.mən/ us/ˌsʌbˈhjuː.mən/
 非人的;不齿于人类的
having or showing behaviour or characteristics that are much worse than those expected of ordinary people
  Their treatment of prisoners is subhuman. 他们以非人的手段对待囚犯。 
 Compare: superhuman