This is the one where Phoebe gives Monica and Chandler the Ms. Pac-Man Game. After playing for 8 straight hours, Chandler's hand is in the shape of a "claw". As soon as he says "I beat every high score, HIGH FIVE!" his hand is in the claw position, yet every time he raises it in the claw position, it goes back to normal as soon as he puts his hand down. You will also notice he even scratches his chin once with the messed up hand.