A barnacle on the ship of progress.
A few photons short of a hologram.
A flash of light, a cloud of dust, and... What was the question?
A legend in his own mind.
A mental midget with the IQ of a fencepost.
A minefield of information.
A modest little person, with much to be modest about.
A natural talent for finding subliminal messages in ice cubes.
A real rocket scientologist.
A statue in a world of pigeons.
A titanic intellect... In a world full of icebergs.
Afraid she'll void her warranty if she thinks too much.
All the personality of a plastic spoon.
Already visualizing the duct tape over his mouth.
Always sharpening his sleeping skills.
Always speaks her mind, so usually she's speechless.
An example of how the dinosaurs survived for millions of years with walnut-sized brains.
An expert on the historical significance of cottage cheese.
Answers the door when the phone rings.
Argues with herself -- and loses!
As popular as a French kiss at a family reunion.
As useful as a cheese sandwich to a drowning ferret.
As useful as bookends down a well.
Beamed down and back up one too many times.
Born too late -- he'd have been a great Neanderthal.
Both oars in the water, but on the same side of the boat.
Brain as busy as a hog farmer in Israel.
Brain permanently in power saving mode.
Built a special showcase for his herd of pet rocks.
Can be outwitted by a jar of Marshmallow Fluff.
Conserves toilet paper by using both sides.
Contributes to collections like this one without searching first to see if their little gem is already listed.
Could qualify as a houseplant if he learned to photosynthesize.
Couldn't find two Saint Bernards if they were in the same telephone booth with him.
Depriving a village somewhere of an idiot.
Doesn't suffer from stress, she's a carrier.
Donated her body to science fiction.
Don't know what his problem is, but it's hard to pronounce.
Driveway doesn't quite reach the garage.
During evolution his ancestors were in the control group.
Finds a flat by swapping tires.
Finds canonical humor collections amusing.
For those who never forget a face, his is an exception.
Goalie for the dart team.
God might still use him for miracle practice.
Got a life, but wasn't sure what to do with it.
Got into the gene pool while the lifeguard wasn't watching.
Has an inferiority complex, but not a very good one.
Has been seen tossing bread crumbs to helicopters.
Has delusions of adequacy.
Has his solar panels aimed at the moon.
Has it floored in neutral.
Has nothing to say, but delights in saying it.
Has over 1000 funny insults saved in a file, but can't remember any of them.
Has the attention span of an overripe grapefruit.
Has the mental agility of a soap dish.
Has the personality of a snail on Valium.
Her display is always flashing 12:00.
Her driver's license says, "Picture continued on other side."
Her friends took her aside, and left her there.
Her IQ is the reason they had to invent negative numbers.
Her lint trap is full.
Her sewing machine's been out of thread for some time now.
His brackets are mismatched.
His brain was sold separately and they were out of stock.
His Corn Flakes have been in the milk too long.
His page was intentionally left blank.
His reaction time is longer than his attention span.
His spirit guide is a three-toed sloth.
His wisdom is stolen from bumper-stickers and T-shirts.
His X, Y, and Z axes don't meet at the origin.
Hitler's evil twin.
Hypnotized as a child and couldn't be woken.
I like him; he reminds me of when I was young and stupid.
I would follow him anywhere, but only out of curiosity.
If brains were chocolate, he wouldn't have enough for an M&M.
If brains were lard, he'd be hard pressed to grease a small pan.
If he were any more stupid, he'd have to be watered twice a week.
If stupidity hurt, he'd go through life on a morphine drip.
If stupidity were a crime, he'd be number one on the Most Wanted list.
In line for brains, thought they said were handing out milkshakes, and he asked for "extra thick."
In the shopping mall of the mind, he's in the toy store.
Invented a pencil with an eraser on each end.
Knitting with only one needle.
Landed with his gear up and locked.
Mind like a steel sieve.
More armpits than brain cells.
Moves his lips to pretend he's reading.
Needed a tutor to learn how to scribble.
Nervous as a long-tailed cat in a room full of rocking chairs.
Never misses an episode of her screensaver.
Not as dumb as he looks, but that would be impossible.
Not only rude, but ugly too.
Of all the things he's lost, he misses his mind the most.
Plenty of salt in the shaker, but no holes in the cap.
Put a lens in each ear and you've got a telescope.
Reading from an unformatted disk.
Requires retraining after every coffee break.
Seen it all, done it all, can't remember most of it.
Settled some during shipping and handling.
She doesn't suffer from insanity; she enjoys every minute of it.
Sings along with elevator music.
Sloppy as a soup sandwich.
Slower than a herd of turtles stampeding through peanut butter.
So dumb, blondes tell jokes about him.
So stupid, mind readers charge her half price.
So ugly, robbers give him their masks to wear.
Sort of like an inverse Einstein.
Still cutting with rounded scissors.
Still traumatized from the forest fire in "Bambi".
Stuck on the down escalator of life.
Stumped by anything child-proof.
The result of years of careful inbreeding.
The sharpest thing he's allowed to play with is a red rubber ball.
Thinks in one-syllable words.
To make him laugh on Saturday, tell him a joke on Wednesday.
Understands English as well as any parrot.
Uses two hands to eat with chopsticks.
Waiting on a toaster that's not plugged in.
Wasn't strapped in during launch.
Whatever kind of look she was going for, she missed.
Where it says, "Sign here", she writes, "Pisces".
Wise as the world is flat.