10 Best TV Characters Who Only Appear In One Scene

Arguably one of the most unmistakable voices in all of the DC Universe can be routinely found falling out of everyone's favourite 'Puddin' in everything from big screen adaptations to much loved animated productions. Should the devilish Harley Quinn arrive on the scene in any of those aforementioned worlds, however, the potential to overshadow just about everyone joining her on-screen is pretty much inevitable.

And that's precisely what went down when the well-known character popped up on The CW's Arrow during Season 2's Suicide Squad episode. Instead of causing chaos and making life hell for all who stood in her path, though, on this occasion Quinn simply dropped a one-liner so good, it pretty much dwarfed everything else that followed in said entry.

As John Diggle and Lyla Michaels squabble about the concept of leading Task Force X, Quinn offers the pair some assistance, brilliantly quipping, "Do you cuties need some counselling? I'm a trained therapist, you know?"

Unfortunately, this tease wouldn't lead anywhere in the end, but it was still pretty cool to hear Tara Strong - the voice of Quinn in many a video game and show - reprising the vocal role here, with Cassidy Alexa physically embodying the part.