Chickens have been a part of the Muppet world since 1972, when the first group of Muppet chickens was created for the Tales From Muppetland special The Muppet Musicians of Bremen. They were precursors to the chickens from The Muppet Show, except they had slightly different eyes. T.R., one of the main characters, would later appear on The Muppet Show as well.
The Bremen chickens were used during the first and second seasons of The Muppet Show. In one episode, guest starring Rich Little, a bunch of real chickens were featured, auditioning for Gonzo's dancing chicken act. It was in this episode that Gonzo developed his obsession with chickens.
During the third season, some new chickens were built with more defined eyes. One of the chickens got the name Camilla and became Gonzo's girlfriend. (Although even Gonzo doesn't know which chicken is Camilla sometimes; they all look alike.)
A black rooster was added to the Muppet Show cast during the second season and a little chick during the third season. In one of the first episodes, guest starring Harvey Korman, a chicken suit was made for the guest star; it would later be used occasionally whenever a huge full-body chicken character was needed.
Sometime during the late 1970s, Sesame Street got its own group of chickens, only they are brown. Another difference from their Muppet Show counterparts is their rounded eyes and sharper beaks. However, the white Muppet chickens did make a few rare appearances on Sesame Street. A brown/black rooster was added later on.
Other notable Muppet chickens are the Giant Man-Eating Chicken from Rocky Mountain Holiday, and the Humongous Chicken from The Adventures of Elmo in Grouchland. The latter was a white chicken with a much smaller head and big, round eyes, but no eyelids. A slightly altered version (donning feminine eyelids) made several subsequent appearances on Sesame Street; one incarnation being Super Chicken. The puppet was later recycled as many more characters on Sesamstrasse.
There is also a small white chicken on Sesame Street with big round eyes. One of its most notable appearances is in Sesame Street 4-D Movie Magic. This chicken was later used in the Dutch co-production Sesamstraat as Stuntkip.
The Muppet chickens usually communicate with squawks, although they are known to speak at times.
The chickens are built without an eye mechanism. Instead, the Muppet builders found an alternative by giving some chickens one wide open eye and one 'relaxed' eye with eyelid; this way, the chicken could change emotions by quickly turning its head.
A baby chick that first appeared in episode 321 of The Muppet Show as Robin with "cluck-itis." He made other appearances in the show, including in episode 504 and various customers in Mopatop's Shop like Kevin on "This Way to the Garden," "Wind," and "The Brave Canary."
- Although Camilla is the only chicken with a regular name and personality, there have been instances where other generic chickens have been referred to by name.
- Gonzo performed a dancing chicken act with a live chicken named Lolita.
- In the audio commentary for "Bohemian Rhapsody," Gonzo mentions that the other two chickens in the video besides Camilla are named Ethel and Stephanie.
- The Tuxedo Gonzo Action Figure by Palisades Toys includes a pack-in figure of a chicken named Bernice.
- In the Muppets Now episode "Fever Pitch," Gonzo introduces, besides Camilla, fellow fowl Priscilla and Miss Stephens.
- In Country Music with the Muppets, a chicken named Louise performs the duty of starting each video clip.
- In Sesame Street Episode 4215, members of the Mostly Poultry t-ball team seek respite from a storm inside Hooper's Store; the names of the four brown chickens are revealed to be Henrietta, Patty, Teri(yaki), and Attila the Hen (Tilly). Henrietta had also appeared earlier in Episode 4127.
- In Episode 3750 of Sesame Street, Madame Alma Cluck and the Poultry Choir performed "Il Alphabetto."
- Selma Worm is a chicken stowaway on the Wiggleprise (she wanted to try out to be a worm astronaut, but it didn't work out).
- Gundel Gackerburg is a pop star chicken who appeared in Folge 2486 of Sesamstraße where Wolle was excited to meet her and hear her sing, but as soon as he hears her horrible singing voice he doesn't like her anymore.
- On Are You Smarter than an Egg Layer? in Sesame Street Episode 4179, the five chicken panelists are named Megan, Jennifer, Kyle, Brittany, and Tandoori.
- Caponata is a full-bodied Muppet chicken on Barrio Sésamo. She is the Spanish equivalent of Big Bird.
- Mrs. Featherbottom appeared in The Furchester Hotel episode "Count Your Chickens" where she went missing from a group of chicken tourists and Elmo and Phoebe had to find her.
- On Vine in 2013, Bert referred to a chicken as Emotional Chicken.
- The 2020 reboot of Takalani Sesame included Chicken, a brown chicken from the same model as on the American series.
- In episode 206 and episode 207 of The Muppet Show, a Giant Chicken appears. Having previously served as a costume for Harvey Korman on episode 110, it reappeared in costume-form worn by Gonzo's boat driver "Margaret" in The Muppets Take Manhattan.
- Charlene is a chicken who appeared in the Mopatop's Shop episode "The Flying Chicken" where she wanted to fly like other birds.
- Hottybotty Hen appeared in the Mopatop's Shop episode "Teething Trouble" as one of the things Mopatop offers in the introduction.
- Two chickens have simply been named "Mrs. Chicken." One of them appeared in the Mopatop's Shop episode "Flowers" to swap the flower she got for the one she wants. The other one appeared in Sesame Street Episode 4153 where Zoe and Rosita think they have turned Maria into a chicken.
- The Muppet Babies episode "Gonzo's Coop Dreams" introduces a trio of chicks called the Bad Eggs. Their leader, voiced by Ben Diskin, is named Patch, because she wears an eyepatch.