"Sesame Street" has had plenty of surprising guest stars over the years, from Katy Perry doing a duet with Elmo to Tina Fey ...

One of the most sought-after lost episodes of “Sesame Street” has been unearthed by Internet archivists, as a rare encounter between Big Bird and the Wicked Witch of the West from “The Wizard of Oz” ...

Frank Oz is the performer behind (under?) some of the most popular Muppets of all-time, including Fozzie Bear, Miss Piggy, and Sam the Eagle, and on Sesame Street, Cookie Monster, Grover, and Bert.