A large clown toy, similar to that scary one in Poltergeist. Contains sophisticated robotics that enable simple movement and speech. Give it to your victim (perhaps a naughty child?) as a gift, and let it lie dormant for a couple of weeks.
Inbuilt sensors will detect suitable conditions (lightning storm, victim is alone etc), and the Clownoid will begin to do its stuff. Beginning with subtle changes in position made when the victim is not looking, it will create the tiniest wisps of doubt and fear in their mind. Next step is to make a strange noise that is just audible to the victim when they are out of the room, so that they come to investigate. This is repeated a couple of times.
Suddenly the Clownoid's eyes light up and it makes a kind of clown laughing sound. This will make the victim jump a bit, but the fear will subside and they will go to it to investigate, thinking "wow, i didn't know it made noises".
Showtime.
Suddenly, as they are looking deep into the clown's eyes everything seems to happen in slow motion. The clown's arms come up quickly to lock around the neck. The legs start kicking. The eyes widen. But worst of all is the voice - deep, scary and screaming, it unleashes a personalised wave of fury and evil, using the victim's name of course, and also saying things that have been carefully selected by the pesky prankster to have the most effect.
As a final touch, the Clownoid would suddenly revert to a limp, lifeless toy, and the victim's family have the option of continuing with the prank by refusing to believe the child and not allowing it to get rid of the thing.
This could be accomplished with existing technology.-- sild, Jan 09 2003 (?) Reminds me of 'Childs Play' http://www.hundland...ildsPlay3-Video.jpgPoor film where a 'possessed' doll kills people. [Jinbish, Oct 04 2004, last modified Oct 05 2004] (?) And of the evil Krusty doll. http://www.geocitie.../Set/5230/sim10.jpg [Monkfish, Oct 04 2004, last modified Oct 05 2004] I'd buy one of these, but only before everyone found out what they were, (+)-- Gulherme, Jan 09 2003 Everyone will have a good laugh when they see the victim dead from a heart attack!-- goober, Jan 09 2003 Venture capital for developing this product was provided secretly by the American Psychiatric Association. (A little way to drum up some custo^H^H^H^H^H patients).-- krelnik, Jan 09 2003 Aah, you remembered. Yes, material of this kind is amongst that which keeps me open-eyed when the darkness comes.-- sild, Jan 09 2003 Didn't RL Stine do this with evil dummies?-- DrCurry, Jan 09 2003 [DrCurry] : I dunno about him doc, but his brother Frank N definitely did.-- Jinbish, Jan 09 2003 I've recently given up caffeine and it has done me all sorts of health favours, but I still don't sleep too good. My mother's Norwegian so perhaps I have some genes from people who used to live in the permanent light up north. But they would still have to sleep though, wouldn't they? I must just be a freak.-- sild, Jan 09 2003 Mmmmmm, I LIKE this idea ....... croissant.-- 8th of 7, Jan 09 2003 My parents belonged to this young farmer's organization awhile back when farming was worth something. The travelling gag gift was this mounted, wooden hand with hinged fingers. For some reason that I'll never figure out, they decided to store the hideous thing in my closet, when I was like, five. Or maybe it was my older sister toying with me, I dunno. Creeped me out for weeks.-- RayfordSteele, Jan 09 2003 [jawa] out of curiosity .... I know I'm going to regret this ..... which part ?-- 8th of 7, Jan 09 2003 So do you have trouble getting your leg to go to sleep?-- sild, Jan 10 2003 When my leg goes to sleep it takes about 30 minutes to wake it up again. I have Norwegian ancestors and also find it difficult to get to sleep sometimes, but once I'm asleep I just don't wake up.-- talen, Jan 10 2003 Looks like we're really on to something here. I'll ask my Norwegian family members what the hell's going on.-- sild, Jan 10 2003 I had Norwegian Ancestors once, but I took some antibiotics and stayed in bed for a couple of days and finally got over it.-- beauxeault, Jan 10 2003 I've got a friend who is scared to death of clowns, so this would be a nice toy to pull a prank on him.-- krigre55, Nov 29 2007 random, halfbakery