1. Got into the gene pool when the lifeguard wasn't watching
2. A few fries short of a Happy Meal
3. An experiment in Artificial Stupidity
4. A few beers short of six-pack
5. Proof that evolution can go in reverse
6. Doesn't have all his Cornflakes in one box
7. The wheel's spinning, but the hamster's dead
8. One Fruit Loop shy of a full bowl
9. One taco short of a combination plate
10. A few feathers short of a whole duck
11. All foam, no beer
12. Body by Fisher, brains by Mattel
13. Has an I.Q. of 2, but it takes 3 to grunt
14. Warning: Objects in mirror are dumber than they appear
15. Couldn't pour water out of a boot with the instructions on the heel
16. Too much yardage between the goalposts
17. An intellect rivaled only by garden tools
18. As smart as bait
19. Doesn't have all his dogs on one leash
20. Some drink from the fountain of knowledge, he only gargled
21. Elevator doesn't go all the way to the top floor
22. Forgot to pay his brain bill
23. Her antenna doesn't pick up all the channels
24. His belt doesn't go through all the loops
25. If he had another brain, it would be lonely
26. No grain in the silo
27. Fell out of the family tree
28. Receiver is off the hook
29. Several nuts short of a full pouch
30. He fell out of the stupid tree and hit every branch on the way down.