"Got into the gene pool while the lifeguard wasn't watching."
"A room temperature IQ."
"Got a full 6-pack, but lacks the plastic rings that hold them together."
"A gross ignoramus - 144 times worse than an ordinary ignoramus."
"A prime candidate for natural deselection."
"A photographic memory, but the lens cover is glued on."
"Bright as Alaska in December."
"One-cell organisms outscore him on IQ tests."
"Donated his brain to science. . . before he was done using it."
"During evolution, his ancestors were the control group."
"Fell out of the family tree."
"Gates are down, the lights are flashing, but the train isn't coming."
"Has 2 brains: one is lost and the other is out looking for it."
"He's so dense, light bends around him."
"If brains were taxed, he'd get a rebate."
"If he were any more stupid, he'd have to be watered twice a week."
"If you stand close enough to him, you can hear the ocean."
"It's hard to believe that he beat 100,000 other sperm."
"One neuron short of a synapse."
"Some drink from the fountain of knowledge. He just gargled."
"Takes him one-and-a-half hours to watch '60 Minutes.'"
"Was left on the Tilt-A-Whirl a bit too long as a baby."
"Wheel is turning, but the hamster is dead."