Kaley Cuoco returned to the Big Bang Theory world with an uncredited Young Sheldon voice cameo

TVLine

Cuoco was the voice of a bacteria-infested pool that taunted Sheldon on the Dec. 13 episode of The Big Bang Theory spinoff. “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,'" co-creator Steve Molaro tells TVLine.