One Scary Dog

I was out walking Molly this afternoon and I ran into the Construction Foreman on the property I live on. Molly usually barks at him every time she sees him for about five minutes until she barks herself out. I was standing there talking to him and Molly didn't make a sound. She took a few steps towards the guy and he started backing up. He says "No offense but your dog scares the hell out of me." Molly evidently tried biting him the first time she ever saw him and that was it for the both of them. How could the cute dog Molly scare anybody?