The Laughing Machine is a large object made of metal. It also has an air bag that helps the person breathe and laugh.
Role in episode
It appeared in SpongeBob's thoughts in the episode "Funny Pants." In his day-dream, Sandy tells Patrick a joke, they laugh and the machine generates a robot laugh. Patrick and Sandy stop laughing and back away slowly. It also appeared in the episode "Suction Cup Symphony" when Patrick was using it while Squidward was showing his symphony to the Bikini Bottomites.