- Not the sharpest knife in the drawer.

- Got into the gene pool when the lifeguard wasn't watching.

- A room temperature IQ.

- Got a full 6-pack, but lacks the plastic thingy to hold it all together.

- A photographic memory with the lens cover on.

- Bright as Alaska in December.

- Fell out of the family tree.

- Gates are down, the lights are flashing, but the train isn't coming.

- He's so dense, light bends around him.

- If brains were taxed, he'd get a rebate.

- If you give him a penny for his thoughts, you'd get change.

- If you stand close enough to him, you can hear the ocean.

- It's hard to believe that he beat out 1,000,000 other sperm.

- One neuron short of a synapse.

- Wheel is turning, but the hamster is dead.