"A collection of insults 20" joke

A semitone flat on the high notes.
A square with only three sides.
A steering wheel / few bolts short of a Yugo.
A teapot with a cracked lid.
A titanic intellect… In a world full of icebergs.
A vacuum-tube brain in a microchip world.
A VGA card and a Herc monitor.
A victim of retroactive birth control.
A violin minus the bow.
A walking argument for birth control.
A wind-up clock without a key.
About half smart.
Afraid she’ll void her warranty if she thinks too much.
Airhead / bubble-brain.
Aliens zapped him with stupidity ray - twice