(I wrote this already; it's copy-pasted here because, well, because I wrote it already.)
My family has a "friend" from Bermuda. He was a friend of my stepdad's mom, and one time my mom mentioned that he should come visit at some point, to which he responded by coming and sitting on our couch and watching terrible television for like three months every winter for ten goddamn years straight. The case of Gosling rum (for my parents) and milk-carton-shaped containers of Whoppers candy (for us kids, whom he mistakenly believed enjoyed them) he would bring as gifts never really seemed a fair trade for this behavior. But anyway:
I was ten or so. I was woken up at 3 AM one night by the creak, creak of someone walking around in the hallway outside my bedroom and this weird sort of hissing noise. It went on and on, and so I crept over to the door and looked through the crack.
He was pacing back and forth up and down the hallway, furiously rubbing his hands together in front of his face and muttering in this subvocal whisper. The only part I could make out was him saying "I KILL you, I KILL you, I KILL you" over and over again. His eyes kept rolling wildly around in his head, and his gait was this weird, halting thing like he was sleepwalking.
Every so often he would stop pacing up and down and stand stock-still in front of my parents' bedroom, his nose about three inches from their closed door. When he did this, this blissful, beatific look would come over his face, and he would roll his head around in what looked like ecstasy. Then the moment would pass, and he would resume pacing up and down, rubbing his hands together and chanting "I KILL you, I KILL you" again.
This went on for an hour or so, or maybe six; I just crouched there, petrified, watching, until he suddenly stopped and shuffled off downstairs. I heard the TV turn on. I tiptoed back into bed and just stared at my ceiling, clutching a metal baseball bat in my sweating hands, until the sun came up.
When people ask me what creeps me out, I tell them Whoppers. Now you know why.