Classic, DynoSaur. Keyringwraiths. Hehe…
CatNymphs. Creatures that are only visible to cats. They get their jollies hanging about in odd places, making bizarre gestures, so the cat will freak you out by staring at them.
Bedusa. They have the ability to turn your pillow to stone with a gaze. Also capable of lowering the temperature of any uninhabited bed to twenty degrees below room temperature instantly.
-Doggerels - cause my canines to wake from a deep slumber and bark at noises/visions that are imperceptible to humans.
-Aviairies - Appear to my parrot and cause him to temporarily go insane.
-Harpies - Music loving fairies that strike single notes inside my piano.
-Buttonymphs - Remove the top collar button from my dress shirts.
Unravellers - Remove the hems from my shirts, trouser cuffs, etc.
-Shampoonies - Drink liquid soap from any sealed container.
-Salad dressing gnomes - Gobble all of the salad dressing, leaving only the empty bottle in the fridge. Also fond of Miracle Whip, steak sauce, and honey-mustard in the squeeze bottle.
Kids these days. No respect for the classics.
Nobody’s mentioned car key gnomes yet???
Perforated Paper Pixies: The fill the last ten percent of any perforation holes in toilet paper, cheque books, kitchen towels etc with magic glue, so when you tear it goes straight at first and then rips off at a 37 degree angle.
Whirling Sock-eater - summoned from the dark recesses of your closet by the hypnotic patterns of spinning clothes, this beast is hungry for only one thing. Left socks. Mysteriously, left handed people usually end up missing their right sock. Go figure.
Oh my god yes!! I made threadspotting!! I did it!!
My thread is on threadspotting!! Hooray! My old handle is on the Straight Dope Home Page!!
Yeeha!
Lucky Charms
I believe the proper name for this beastie is the Socktopus. Not to be confused with the sockhopper, which causes your left socks to leap directly from the laundry to the mysteriouss, unknown city of Sockopolis, which is constructed entirely of left socks. :eek:
The Litterbox Lamia - proven by the fact that mere moments after I scoop the catbox, there is a fresh deposit therein, judging from the size of which could not have possibly come from my solitary cat.
Caller IDemons: They make the phone ring when you are to busy to answer it. If you make the mistake of trying to check who is calling you… “Unknown name, unknown number.”
That’s a classic.
Can’t believe nobody’s mentioned the Leprechaun on the Ceiling yet. He doesn’t do anything, just sits there, totally oblivious to the law of gravity. I hate that little prick!
The Fruit Bowl Boggart, you start eating fresh grapes in Roman Emporer style whilst watching your favourite Black & White movie and as you become transfixed by a crucial plot moment you pop a grap in your mouth, to find it’s rotten.
For some reason, the idea of this thread reminds me of things from Krisfaluci-era episodes of Ren and Stimpy, like the Tooth Beaver and Magic Nose Goblins. That’s all the insight I have.
Milkjuggernauts. They make just enough milk disappear that you think there’s still plenty, only to pour just enough on your cereal to get it a little damp.
Most of y’all can’t relate, no doubt, but I assure you that the Diaper Genie Genie fills up the Diaper Genie to the rim, when you’re expecting company who also have small children, when you know good and well you just emptied it.
Still chuckling over the Keyringwraiths…
Notebook Nymphs. I think these like to inhabit 500 series PowerBooks, destroying them from within. It’s the best explanation for why the replacement parts for my 540c keep coming with damaged hinge mounts.
Pornography Poltergeists. These, left unchecked, will cause your personal porn collection to become evident to your SO/mom/friends, causing embarrassment.
Coffee Faries. These are responsible for the unexplaned metallic taste in your coffee, even after you started brewing with distilled water.
When your computer screws up, it’s the pixel pixies.
Patch cord cuckolds. 
These make random connecting cables in stereos and computers just a little flaky, so that the equipment sometimes malfunctions. You know something’s wrong, but you just can’t pin it down.
I see we’ve nearly forgotten robinshees, those invisible birds only your cat can see, the ones that make him/her go running through the house faster than if you said the dirty word “B-A-T-H”.
Then, there are also polterkittens, those things that make you trip in the kitchen when you can’t see any cause for you to trip.
Finally, my VCR is haunted by the “Poltergeist” poltergeist – it turns itself on and off, plays movies, tries to record television programs, does damn near everything but dust itself and reset its clock, and does it all completely without any human intervention. . .I’m just waiting for the day Craig T. Nelson manages to stick his head out of the cassette slot and says “They’re heeeeeeeerrrrreee!”
Beware - BEWARE - The dreaded URL-RonHubbard, 
which takes all the money you made from those “send this email to ten friends” deals and forces you to believe that cosmic radiation is coming from the monitor, then have sex in order to harness the energy. Hey, wait a minute… 
Sh-harpees - those fiendish precogniscient imps who make sure that you see a rarely used writing instrument or tool several days or weeks before you need it. Then when you need it and go to look…they’ve moved it, leaving you to wonder if you’re going mad.
Sure sign that a Sh-harpee has been messing with you…you wander around searching through drawers and closets muttering “I know I just saw that thing recently…”
Reading this thread has reminded me of a skit on an old time radio show I heard a long time ago, about household gremmites: creatures that are born when the smallest gremlin breeds with the largest termite. There are two particular gremmites, a French gremmite and a Chinese Gremmite. The French one makes the tap in the kitchen drip all night long. His name is Fau’Cett. The Chinese one makes loose plaster fall onto your head. His name is Cei Ling. <<drum roll and cymbal crash>>
KeyRingWraiths: Hilarious! Especially in light of the upcoming Lord of the Rings movies.
Saryl