Answer: cerberus

AnswerCrossword Clue
CERBERUSHade's watchdog
CERBERUSThree-headed watchdog of myth
CERBERUSThree-headed dog of Hades.
CERBERUSSinister three-headed dog of myth.
CERBERUSVigilant guardian.
CERBERUSChallenge for Hercules.
CERBERUSMythical figure
CERBERUSMythical dog guard of Hade's door