WARNING: TRY THIS AT YOUR OWN RISK
How to summon Jeff The Killer: (Note this must be done in your bedroom.)
Wait until midnight. Take a kitchen knife and go up to your bedroom. (Make sure everyone in your house is asleep), close the door and make sure there is moonlight shining through your window.
Lay down on the bed and cover yourself with the blanket(s). Hold the knife were your heart is. Close your eyes and chant:
Jeff the Killer Jeff the Killer Jeff the Killer
You will here a voice whisper: "Shhhhh... Go to sleep."
Then, open your eyes.