I should have known

It was the summer of 1997, me and my wife were getting ready to go to Australia, I went into my son's room to wake him up but he was not there.I told my wife about it and she said "What do you mean?" She had a shocked look on her face and then she said "Do not look behind you" I was very confused. Then I heard my son screaming and then he just went silent. We rushed downstairs only to find his body without his head then we saw it. It was horrifying the creature had no eyes but it had very very sharp teeth. We then sprinted outside and ran to the local police station. They did not believe us. I was charged with his murder. My wife was asked questions but she just said "There was this thing I told my husband to not look behind him. It then climbed up the wall and ran down the stairs it ripped my son's head off and ate it. We thought our son was in his room but he was downstairs eating breakfast. We think that thing was in our house all night. My husband saw it and ran out of the house and he could be dead in his cell right now because of you stupid police officers!" Then It came into the police station. People were screaming! Blood was going everywhere! Guns were shot! That thing just would not die! It then was outside my cell, I knew I was going to die, but it didn't come in my cell, it just growled at me. I was horrifed. It then sprinted out of the station faster then a motorbike.It was all over the news about that monster! I let out and they investigated it. Me and my wife will never forget that day. I should have known that it was always here. This is the last thing I will write before I die but it told me it's name.
It is the Knightmare.
{{By-cpwuser|1dayleft}}