A few fries short of a happy meal

A few beers short of a six pack

Dumber than a box of hair

Doesn't have all their cornflakes in one box

The wheel's spinning but the hamster's dead

Not the coldest beer in the fridge

One fruit loop shy of a full bowl

All foam, no beer

Has an IQ of 2 but it takes 3 to grunt

Couldn't pour water out of a boot with instructions on the heel

An intellect rivalled only by garden tools

The chimney's clogged

The elevator doesn't go all the way up to the top floor

Their antenna is not picking up all the channels

Proof that evolution can go in reverse

Not the sharpest tool in the shed

The lights are on but nobody is home

The light at the end of the tunnel has gone out

2 sticks short of a bundle

The cable is connected but there is no voltage

Swimming in the shallow end of the gene pool

One neuron short of a synapse

An experiment in artificial stupidity