Wow! 'Young Sheldon' Just Had a Kaley Cuoco Cameo & You Didn't Even Realise It

Usually when we have two popular shows coming together there's a huge buzz about it and promoted too.

But that didn't happen recently as Kaley Cuoco aka Penny just made a secret Cameo in Young Sheldon.

In a December episode of the CBS comedy, Kaley Cuoco appeared—voice only—in a dream of young Sheldon (Iain Armitage). Cuoco, who played Penny on The Big Bang Theory for 12 seasons, voiced the pool monster.

"That was absolutely the voice of Kaley as pool water," Young Sheldon co-creator Steve Molaro told TVLine. "I needed someone to do the voice. I knew I wanted it to be female and kinda sexy, and I said, ‘Well, duh! Kaley is perfect for this.'"

Molaro said he and Cuoco decided to keep the role hush hush. "Sometimes I feel a little weird about things being over-promoted, and as awesome as it was, I don't know that that should be the kind of thing that appears in promos," he said, noting it was an easter egg for fans to find.

The Thursday, Feb. 20 episode of Young Sheldon had another big nod to the mothership show. Sheldon and dad George (Lance Barber) visited California Institute of Technology and in a nod of what's to come, visited the cafeteria viewers would come to see many times on The Big Bang Theory.

"Imagine all the stimulating conversations that must go on at these tables. I can see myself going here one day," Sheldon said looking at the lunchroom.

"I think you'd fit right in," George said. Then the camera panned out to reveal the fan-favorite set and table Sheldon (Jim Parsons), Leonard (Johnny Galecki) and Co. would spend many a scene at.

In an interview with TVLine, Molaro said it was the original Big Bang Theory set on loan from the Warner Bros. museum.

"It was more than a bit [surreal]. I can tell you that it was extremely emotional. I knew it was coming, and I walked to the stage that morning and immediately started welling up with tears as soon as I saw it. For me, I said a very heartfelt and tearful goodbye to those sets 10 months ago, and never imagined that I'd be seeing and sitting on one again… Before we even started rolling, as soon as I saw it, I was a mess," he said.

Did you manage to catch the cameo? Leave in your comments below.