S2 E10 – "A Proposal and a Popsicle Stick Cross" (Aired: December 6, 2018)
8/10
After Paige points out that people with "stunted childhoods" often grow up to be social misfits and "weirdos," a panicked Sheldon decides he must learn how to act like a child. His mission leads him to a comic book store, where he discovers a display for novelty pranks. Taking the brand name literally as a signifier for humor, Sheldon begins a series of failed but hilarious pranks:
"The PTA Disbands"
He makes a "Is your refrigerator running?" phone call.