The CW's "Arrow" has had a few clear links to the greater DC Universe, especially when it comes to Batman-related mythology. The League of Assassins and Ra's al Ghul have both been important in building the show's story throughout the first and second seasons, but perhaps there's no clearer link to Bruce Wayne's world than a brief line of dialogue in this week's "Suicide Squad" episode. A clip posted by Comic Book Movie highlights the scene in question, which features John Diggle (David Ramsey) and Lyla Michaels (Audrey Marie Anderson) arguing over bringing Deadshot on to serve as part of the Suicide Squad, when a familiar voice breaks the conversation:

"Do you cuties need some counseling? I'm a trained therapist!"

According to the episode's IMDB credits, that voice is none other than Tara Strong, veteran voice actor and voice of Harley Quinn in the "Batman: Arkham" video game series and "Injustice: Gods Among Us." The character's appearance could mean big things for the future of "Arrow" and serve as a much stronger tether to help introduce elements from Batman's side of the DCU.

Bringing in Harley Quinn would be a good move for the series based on how well the character has done in the comics market in recent months. The "Harley Quinn" ongoing was in the top ten bestselling comics for its #0, #1 & #2 issues, just barely missing the top 10 cutoff for its third in February.

That said, manage expectations accordingly -- executive producer Marc Guggenheim spoke with Collider about the cameo, saying it was meant to be more of an Easter egg than anything else. He doesn't rule out Harley coming back, though.

"I want to manage expectations with respect to Harley Quinn," Guggenheim told Collider in response to a question about using Batman characters now that "Gotham" has begun production. "She was always intended to be an Easter egg. I don't want people to go in with incorrect expectations and walk away from Episode 16 disappointed. But there is an element to the Easter egg that was not spoiled by the promo, that I think people will find a lot of fun."

Check out the clip below and judge for yourself as to whether Harley's due for a full appearance on "Arrow."