"Well," you hesitate, "yeah, I've seen him." You explain to the officer that you had a horrible dream the previous night in which the man burst into your home and attacked you, then was killed in the ensuing struggle.
"Ah, I see," the policeman says. "Sounds like you're prone to nightmares."
"Not all the time," you confide, "but I do have some pretty scary ones."
"Yes, you do," he answers as his head starts to split open, revealing a huge maw full of row after row or razor sharp teeth. You turn to run, but he reaches out with the long arm of the law and catches you. His hands have teeth now, too, and he's already eating you before he even pulls you in.