Snopes, that essential guide to our culture's depth, shares this excellent scary clown urban legend:
A couple with children were trying out a new babysitter. About an hour after they left for a night on the town, they realized they had forgotten to give her their cell phone number, so one of them called her.
After she wrote down the number, the babysitter asked if she could watch satellite TV in their bedroom. She had just put the children to bed and wanted to watch a particular show. (The parents didn't want their children watching too much garbage, so the living room TV did not have satellite channels.)
Well of course she could watch TV in their room, they replied. The babysitter had one other request: could she put a sheet or blanket over the clown statue that was in the bedroom? It kind of made her nervous.
Take the children and go to the neighbors, said whichever parent was talking to her. We'll call the police. We don't have a clown statue. The police caught the clown as he was running through the neighborhood.