Mr. Big made an appearance in episode 2929 of Sesame Street. His size contradicts his name in that he's actually a very small man. He is named so because he deals in big things (plus he enters with loud, giant-like footsteps). He first appears to Telly Monster, who found his huge watch for him. Then he takes himself to Hooper's Store and infests it with his items to the chagrin of Gina and Mr. Handford. They include a gigantic coffee cup, an immense pencil, a stupendous fork, and a gargantuan telephone.
At one point, however, Mr. Big's products come in handy, when he supplies Snuffy with an enormous toothbrush. Finally, the store proprietors insist he get rid of his oversized merchandise. He obliges and has them help him load the whole kaboodle into his surprisingly miniscule car.