The Predator was first designed by a special effects company the studio picked to save money on. Stan Winston later created the Predator for $1.5 million; this other studio charged half that amount. Because of that, their Predator looked like someone in a lizard suit with the head of a duck, according to Arnold Schwarzenegger.
When Winston was brought in to redesign the Predator, the final fight scene had to be reshot. The new Predator was 8-1/2 feet tall, but the recast Kevin Peter Hall was 7'2". The costume was heavy and off-balance and Hall couldn't see with the mask on; because of that, during the fight scene with Dutch, he actually did hit Schwarzenegger once.