The Best Time Penny Ever Broke Character On The Big Bang Theory

Real fans of "The Big Bang Theory" know that the finished product of the show itself is only one source of its comedy. The series ran for an incredible 12 seasons and 279 episodes, which, as one can imagine, means countless hours of filming. And all that filming means that there are lots of bloopers.

Similar to other sitcoms such as "The Office," bloopers for "The Big Bang Theory" have a life of their own. Whether it's a scene grinding to a halt because of a forgotten line or a bungled character entrance, watching Johnny Galecki, Jim Parsons and the rest of the gang joyfully messing up while filming the show can, at times, be almost as fun as the show itself. The characters are so big and specific that watching the actors break creates some pretty special moments.

That, of course, is very true for Kaley Cuoco. Between her run as Penny on "The Big Bang Theory" and her recent success with HBO Max's "The Flight Attendant" (where she impressed her co-star Rosie Perez with her professionalism), she has more than proved that she has formidable comedic chops. Even when she's messing up in a scene she's making us laugh.

There are a lot of hilarious Penny "Big Bang Theory" bloopers to choose from, but one particular musical slip-up is our pick for the best of them all.

Kaley Cuoco hits a wonky note while singing "Soft Kitty"

One of the sweetest running gags on "The Big Bang Theory" is a little song called "Soft Kitty." The cutesy nursery rhyme was Mary Cooper's (Laurie Metcalf) go-to song to sing when Sheldon was feeling sick. As an adult, he still requests that people sing it to him when he's ill and in bed. As though seeing grown adults sing each other a song that goes "Soft kitty, warm kitty, little ball of fur," weren't funny enough, watching Sheldon drop his typically abrasive demeanor while being soothed by the tune is also a treat.

In the episode "The Cruciferous Vegetable Amplification," Sheldon has decided to try and cheat death by remaining in his room and sending a robot with video chat capabilities out into the dangerous world on his behalf. The tag at the end of the episode sees the Shelbot "knocking" on Penny's door to ask her to sing "Soft Kitty," as Sheldon is bed-bound with a sprained ankle.

In a blooper for that scene, Penny's rendition of the song goes a bit haywire. After singing the first few words, Sheldon asks her to move closer to the microphone. She obliges, but when Cuoco begins the song again, she hits a bum note that immediately breaks her out of the scene. The break is clearly unexpected and watching Cuoco playfully grimace at her own mistake makes it all the more enjoyable.