During the 1988 Christmas season, the Koosh ball was the hottest toy on the shelves. The Koosh ball was a rubber ball filled with a jelly-like plasma and its outside consisted of hundreds of rubber spikes making it look like a soft and flexible porcupine that did not hurt to hold or squeeze. When someone squeezed the object, the plasma caused it to squirm around in his hand while the spikes provided something to grip in one's hand.