When the Muppets first began, they started as fully-formed characters with no set age, though were clearly in their adult stages. Though characters, such as the Muppet residents of Sesame Street, are given set ages, they've remained the same age and look since their debut. As such, the subject of the characters' ages versus their physical appearance has been referenced many times for the sake of a joke.
- The Muppets: A Celebration of 30 Years honors Kermit the Frog's 30 birthday, as well as the entire Muppet family. However, Miss Piggy denies being grouped with them, explaining "there's no way moi could be 30" and adds that she is a "child star" because her debut on The Muppet Show was 10 years prior. Harry the Hipster also questions how Kermit looks better currently than he did on Sam and Friends. "That's one of the advantages of being a Muppet," Kermit responds.
- In Sesame Street: 20 and Still Counting, Bill Cosby asks Big Bird how he's remained six years old for (then) 20 years. Big Bird replies, "Just lucky, I guess!"
- On an appearance on The Tonight Show in 1996, Jay Leno asks Kermit how he retains his youthful look. Kermit claims frogs age at a different rate from humans and he makes two annual visits to an anti-aging clinic where "they rub [him] up against Dick Clark." He adds his exercise regimen helps, performing leap frog.
- In a 2005 appearance on Rove Live, Rove McManus compliments Grover's appearance after 35 years of Sesame Street. Grover notes it's because of his workout routine and remarks, "You do not get a body like this naturally, you know." He is however able to do more than one push up afterward.
- In the opening sequence of The Muppets, Walter and Gary's childhood is shown. While Gary ages throughout the sequence, Walter physically remains exactly the same, hinting at his Muppet roots. Later in the "We Built This City" montage, Fozzie Bear comes across an old photo of himself in the Muppet Theater. He laughs at his "80s haircut," unaware that he looks almost exactly the same.
- Bert and Ernie are asked about their age on a 2014 appearance on Oprah: Where Are They Now?. They simultaneously give different answers (Bert, 52 and Ernie, 25).
- In a 2016 appearance on Last Week Tonight with John Oliver, John Oliver acknowledges to Elmo and Rosita that their resource video, Lead Away!, was released 20 years ago and compliments their youthful looks. Rosita claims she uses moisturizer and Elmo chalks it up to his gym trips.
- At a 2016 appearance at Vulture Festival, Fozzie claims he goes to a fur colorist to keep his youthful looks. Kermit attributes his to running from Miss Piggy for many years.