"A collection of insults 29" joke

Perfect percussionist for an acapella group (duh, duh, duh...)

Perfect training subject for apprentice hypnotists.

Permanently out to lunch.

Permanently rotated 90 degrees from the rest of us.

Phototrophic on a better day.

Pins 2 and 3 (RS-232) permanently connected to ground.

Playing an endgame with a king and no other pieces.

Playing baseball with a rubber bat.

Playing hockey with a warped puck.

Playing Scrabble, but we can't figure out what words he's building.

Plays pinochle with a poker deck.

Plays solitaire... for cash.

Plays tennis with no net and finds it challenging.

Plenty of myelin but not enough neurons.

Plenty of salt in the shaker, but no holes in the cap.