Sesame Street’s Elmo turned 3-and-a-half Feb. 3, despite being introduced on the show in 1980. Here’s the reason why his age stays so specifically fixed.

If you're curious about how Sesame Street has evolved, we've compiled a list of its most popular characters—ones you're sure to spot the next time you sit down to watch with your kids.

Appearing on “Sesame Street”? That’s the best idea. The 55th season of the acclaimed family program features a star-studded lineup of ...