Eric the Clown is a young man who was hired by George Costanza to entertain the children at a birthday party for the son of his current girlfriend Robin. Being a clown is just a gig to Eric and is not his life calling. Eric the Clown was played by Jon Favreau and his sole appearance was in Season Five's "The Fire".
George Costanza got into an argument with Eric the Clown when Eric told him he did not know who Bozo the clown is. Eric took offense at George's pestering and told him to stop hassling him. George did so, but not before mocking him for choosing 'Eric' for a clown name.
Later on, a fire broke out in the apartment where the party was being held. George was frightened by the fire and he pushed Eric the Clown and several other party guests down to the ground as he stormed out of the apartment in sheer terror. Eric the Clown kept his cool, however, and noticed the fire was just some overcooking hamburgers in a pan on the stove. Eric the Clown saved the day when he removed one of his large clown shoes and used it to beat at the fire until it was extinguished.