8 Amazing TV Characters That Were Only Supposed To Appear In One Episode

Though Felicity Smoak is a character from DC comics, it's unlikely that many fans of Arrow were familiar with her when she debuted in the show. She was intentionally picked from relative obscurity to be adapted for the series partly because the writers needed a tech-based character for a very brief role in a single episode.

Had they expected Smoak to be around for as long as she was, they might have picked a bigger name - but in hindsight that would have robbed superhero fans of one of the best characters on The CW.

Emily Bett Rickards was cast in the minor role - which was literally only two scenes initially - but instantly became a hit with the cast. Her chemistry with the rest of the team and her performance on the day was noted by other cast members and even the chairman of Warner Bros.

Once the episode aired and Smoak was embraced by fans and critics, it didn't take the writers long to flesh the character's role out and bring her back for more episodes, with her presence growing as the seasons wore on.

Eventually, Smoak became a vital character not only in Arrow, but the entire DC TV universe at large, crossing over onto other shows such Legends of Tomorrow and Supergirl.