It’s time to play the music, it’s time to light the lights…and check out these stories about how a bunch of those beloved Muppets were created.

Cookie Monster

In 1966, Muppets creator Jim Henson designed three monster puppets for use in a commercial for a snack product called Wheels, Crowns, and Flutes. Each puppet corresponded to the Wheels, Crowns, and Flutes—the Crown-Grabber stole Crowns, for example. The commercials never aired, but Henson recycled the puppets into other avenues, particularly “The Wheel-Steeler,” used in “The Coffee Break Machine,” an IBM training film—the character eats a gigantic computer as the narrator describes how it works. The puppet showed up again in an ad for Frito-Lay’s Munchos, devouring chips as a monster named Arnold. In 1969, Frito-Lay asked Henson to make more Arnold commercials but he opted not to, because he wanted to transform Arnold into the “Cookie Monster” for his new educational children’s show, Sesame Street.

Miss Piggy

Miss Piggy. Veteran Muppet builder Bonnie Erickson had to create a strong and feminine Muppet to perform a duet with Herb Alpert for a 1974 TV special, and she was inspired by 1940s and ‘50s jazz and pop singer Peggy Lee. The “Fever” singer was also widely known as Miss Peggy Lee, so Erickson made a pig Muppet and called her Miss Piggy Lee. “Peggy Lee was a very independent woman, and Piggy certainly is the same,” Erickson told Smithsonian magazine. After the character became more popular, the “Miss” was dropped because Erickson didn’t want to offend the real Miss Peggy Lee.

Fozzie Bear

Wocka wocka wocka! The woefully inept, self-doubting, vaudeville-style stand-up comedian bear was operated for years gets his name from Faz Fazakas, the Muppet builder who devised the mechanism that allowed puppeteers to electronically wiggle their Muppet’s ears. That mechanism was first used on Fozzie Bear as a way to “accentuate” his terrible jokes.

Swedish Chef

“Bork bork!” That’s just one example of the “mock Swedish” that the Swedish Chef speaks while he’s making a mess in the kitchen on The Muppet Show. Jim Henson’s son and Muppet performer Brian Henson says that the idea came from the elder Henson’s love of a cassette called “How to Speak Mock Swedish.” Henson would play it in the car and riff on it while it was playing, using mock Swedish to pretend to “make a chicken sandwich” (or “merk a cheeky serndwerch”). Eventually, Henson applied the bit to a puppet.

Kermit the Frog

Henson’s first professional gig—at age 18—was a late-night Washington, D.C. show called Sam and Friends. Among the many puppets he created for that 1950s show was a lizard-like character he named Kermit after a cameraman who worked at the station where Sam and Friends taped. Henson made what would become the quintessential Muppet out of an old coat his mother didn’t want anymore, with eyes made out of a table tennis ball cut in half.