· About as sharp as a marble.
· A few clowns short of a circus.
· Not the brightest bulb on the Christmas Tree.
· A few fries short of a Happy Meal.
· I wish I had a blueprint for his brain; I'm trying to build an idiot.
· An experiment in Artificial Stupidity.
· He only has one oar in the water.
· A few beers short of a six-pack.
· Dumber than a box of hair.
· A few peas short of a casserole.
· Doesn't have all her cornflakes in one box.
· One Fruit Loop shy of a full bowl.
· One taco short of a combination plate.
· A few feathers short of a whole duck.
· All foam, no beer.
· The cheese slid off her cracker.
· Body by Fisher, brains by Mattel.
· Couldn't pour water out of a boot with instructions on the heel.
· He fell out of the Stupid tree and hit every branch on the way down.
· An intellect rivaled only by garden tools.
· As smart as bait.
· Chimney's clogged.
· Doesn't have all his dogs on one leash.
· Elevator doesn't go all the way to the top floor.
· Forgot to pay his/her brain bill.
· Her sewing machine's out of thread.
· His antenna doesn't pick up all the channels.
· His belt doesn't go through all the loops.
· If she had another brain, it would be lonely.
· Missing a few buttons on his remote control.
· No grain in the silo.
· Proof that evolution CAN go in reverse.
· Receiver is off the hook.
· Several nuts short of a full pouch.
· Skylight leaks a little.
· Slinky's kinked.
· Surfing in Nebraska.
· Strong like bear... Smart like tractor.
· Too much yardage between the goal posts.
· Not the sharpest knife in the drawer.
· The lights are on, but nobody's home.
· Has an IQ of 2, and it takes 3 to grunt.
· Warning: Objects in mirror are dumber than they appear.
· Doesn't know much, but leads the league in nostril hair.
· 24 cents short of a quarter.
· The wheel's spinning, but the hamster's dead.
The last one is my favorite.
