Despite Easter Eggs and nods to The Big Bang Theory (TBBT) being popular in spin-off show Young Sheldon, not many fans picked up on Kaley Cuoco's secret cameo. Cuoco, who played Penny in TBBT, lent her voice to a 'seductive' swimming pool in a dream sequence of Young Sheldon. In this feverous nightmare, Sheldon, fearing disease from his school swimming pool, has a surreal interaction triggering his fear of water. Close listeners may have identified Cuoco's distinctive voice luring anxious Sheldon closer, just before a huge water hand drags him under. Waking in fear, Sheldon screams "pool monster" and ends up faking illness to avoid the swim test. Co-creator Steve Molaro revealed that only Cuoco had the 'female and kinda sexy' voice he envisioned for this eerie moment. Both agreed to maintain an air of mystery by keeping Cuoco's name out of the credits. This clever cameo delves into Sheldon's fear of water, lending backstory to TBBT's Sheldon's unconventional methods of learning to swim on dry land.