Who Did The Walking Dead's Steven Yeun Play In The Big Bang Theory?

These days, Steven Yeun is a household name with several notable credits to his name. If you don't know him from "The Walking Dead" or "Beef," odds are you recognize him from "Sorry to Bother You" or "Nope," among other titles. All of that is to say that Yeun has quite an impressive filmography, populated by roles and projects moviegoers and television viewers have yet to forget. At the same time, there are a few acting endeavors of his that have understandably slipped by the wayside, such as his one-off appearance on "The Big Bang Theory."

Before becoming a globally-known Hollywood star, Yeun popped up in the "Big Bang Theory" episode "The Staircase Implementation." In a flashback sequence, he plays Sebastian, who doesn't seem to have very positive feelings on his former roommate, Sheldon Cooper (Jim Parsons). As the pretty terrible Leonard Hofstadter (Johnny Galecki) makes his way toward what ultimately becomes his and Sheldon's apartment, Sebastian warns him not to bother. In fact, he urges him to run away and run far, though, evidently, Leonard doesn't take this advice to heart.

Beyond "The Staircase Implementation," Yeun doesn't reemerge on "The Big Bang Theory," which seems like a missed opportunity given his comedy skills.

Since his lone "Big Bang Theory" appearance, Steven Yeun has found his footing in Hollywood through more dramatic efforts. The likes of "Minari" and "The Humans" have allowed him to sharpen his drama skills in various ways, but he hasn't pigeonholed himself by any means. Yeun is also quite accomplished when it comes to comedy works as well, voice acting on "Robot Chicken" and "Final Space" and appearing in the flesh on "Weird City" and "Drunk History," for instance. He's likely done so well on such projects because of his comedy education.

When he was just starting out as an actor, Yeun joined the Chicago, Illinois improv comedy staple known as The Second City. For those unfamiliar, this troupe has brought audiences such comedy legends as John Candy, Chris Farley, Tim Meadows, and numerous others, so it's safe to say that if Yeun wanted to learn comedy, he was in the right place. He admitted to The Guardian that breaking into the entertainment world through comedy didn't quite pan out at first, but luckily, he's been able to explore his comedic horizons more and more as his career has gone on.

Steven Yeun didn't stick around on "The Big Bang Theory" for long, which seems like a shame given how well he could've done with its comedic writing. Then again, given the career he's had since, it's safe to say he didn't need it that badly anyway.