The Big Bang Theory Easter Egg You Missed In DC's Harley Quinn

Saying goodbye to a show you've been watching for over a decade feels like a very real loss. Obviously it's not like losing a family member or even a pet, but it's the same emotional black hole you feel when, say, your favorite chair breaks beyond repair, or when you find out that your favorite food has been discontinued.

It's even more difficult for the cast members, especially when they all get along with each other. So when when The Big Bang Theory wrapped in 2019 after 12 seasons, Kaley Cuoco found a way to bring a little bit of the show with her into her next project — and it's one that her former co-stars' characters would have appreciated.

Just months after The Big Bang Theory's final episode aired, the animated series Harley Quinn kicked off with an expletive-laden bang on the DC Universe streaming service. Cuoco voices the titular anti-heroine, who's taking control of Gotham with help from King Shark (Ron Funches), Clayface (Alan Tudyk), Poison Ivy (Lake Bell), and Dr. Psycho (Tony Hale). But that doesn't mean Cuoco has forgotten her old gang of BNFF (that's best nerd friends forever). Here's the Big Bang Theory Easter egg you missed in DC's Harley Quinn — and a DC Easter egg you may have missed in The Big Bang Theory.

The Big Bang Theory had a lot of in-jokes and clever references throughout its 12-season run. But one that stuck from the very first episode to the very last was the broken elevator in Sheldon (Jim Parsons) and Leonard's (Johnny Galecki) apartment building. This joke even predated Cuoco's character Penny. Sheldon and Leonard have just finished climbing the stairs (with some helpful stair facts from Sheldon to keep them going) when they first see Penny unpacking in the apartment across the hall.

Cuoco paid tribute to this long-standing gag as Harley Quinn. In one scene, Harley interrupts a rooftop meeting between Gotham Police Commissioner Jim Gordon (Christopher Meloni) and Batman (Diedrich Bader), notably out of breath. "What's the point of having an elevator if it doesn't work?" Harley seethes. The Big Bang Theory crew do have something in common with their favorite superheroes after all.

Cuoco's role as Harley would have delighted some of the characters in The Big Bang Theory, including Penny — it's an acting gig, right? And it's especially appropriate given the show's long connection with DC Comics.

When The Big Bang Theory started in 2007, the movie world was in a superhero rut. Catwoman had bombed in 2004, the Tobey Maguire-starring Spider-Man 3 had wrapped up that trilogy a few months earlier, and The Dark Knight wouldn't come out until the following year. The X-Men franchise was the brightest spot on an otherwise spandex-and-superpowers-free landscape. But by the time the show ended in 2019, superheroes had become the most lucrative genre in Hollywood. Five of the highest-grossing movies of all time in the U.S. are superhero movies — and four of those are Marvel (one is Pixar.)

Even while Marvel was outdoing DC at the box office and with critics, the Big Bang Theory crew remained steadfast DC supporters. They do occasionally discuss Marvel movies (there's a whole scene in which they try to figure out a time to watch Avengers: Endgame), but they frequently dress up as DC characters. Of course, Penny went with Wonder Woman over Harley, which would have been an uncanny prediction. Sheldon's expansive t-shirt collection also doesn't have room for Marvel heroes.

It's worth noting that the reason for this preference is business rather than personal. The Big Bang Theory is a production of Warner Bros. Television, meaning the show shares a parent company with DC Entertainment. So while Bernadette (Melissa Ivy Rauch) can lust over Thor, the closest she'll get to him will have to involve a pair of 3D glasses.