The core group of characters within The Walking Dead has obviously changed and evolved over the course of the series, but from the very start, they have been the driving force behind the story and development in the show.
However, that doesn't mean that more minor characters haven't had the opportunity to shine either. Although these particular characters may not have appeared in many episodes or had a lot of screen time, they are some of the most memorable characters in the eyes of The Walking Dead's fans.
Guillermo - 1 Episode
Obviously The Walking Dead's narrative has a tendency of focusing on the worst that's left of humanity after the apocalypse has destroyed the world. However, there are some rare characters that stick out for good reasons instead of bad ones, and Guillermo is one of the best of them.
Appearing in the season 1 episode "Vatos," Guillermo and his crew initially seem to be a group of unscrupulous thieves, only to be revealed as a squad of tough guys protecting a bunch of immobile elderly people. They serve as a candid reminder that the main group aren't the only good people left in this post-apocalyptic world.
Clara - 1 Episode
The zombie version of Clara made a few appearances in other episodes of The Walking Dead, but the living version of the character only needed one episode to make a strong impression on the audience.
Rick was on a bit of a symbolic mission and was determined to believe that no one in the world is too far gone, but Rick's faith in that idea is tested when he realizes that Clara has been keeping her walker husband's severed head alive, and she plans on making Rick his next meal.
Duane - 1 Episode
Duane Jones was introduced in the pilot episode of The Walking Dead, and although he was dead and gone by the time that Rick managed to actually reconnect with Morgan, Duane's influence on the story at large can't be overstated.
As a clear mirror to Rick and his relationship with Carl, the Joneses were a signal of hope for Rick's future at the start, and the loss of Duane that drove Morgan to madness was a real dark point for the series.
Eastman - 1 Episode
Morgan understandably did not cope well when he lost his wife and son, and when Rick found him in "Clear" it seemed like all hope was gone for the man who had helped Rick at the start of the apocalypse.
But, Morgan eventually returned and was himself, and it was revealed that Eastman was the one who largely set him on his path toward recovery. It's always impressive when a show manages to make a one-off character have a huge impact and makes them feel like a genuine and painful loss, and Eastman's death felt like a sincere tragedy despite his presence only lasting for one episode.
Lucille - 1 Episode (So Far)
Actress and real-life wife of Negan's actor, Jeffrey Dean Morgan, Hilarie Burton Morgan is already slated to appear in at least one other episode of The Walking Dead. But, fans had been eager to see the story of the real Lucille brought to their screens ever since Negan was introduced into the series, and it's safe to say that she didn't disappoint.
Equal parts loving and badass, it wasn't hard to see why Negan was utterly crushed at the loss of his wife. Now that he finally seems to be getting back to his old self and has fallen in love again, it'll be interesting to see what role Lucille plays in his future on the show.
Otis - 2 Episodes
The ultimate role that Otis played in the journey of the core group is a fascinating one, because had he not almost killed Carl Grimes, then the group never would have become what it was.
Otis was a kind and caring man who was willing to put himself on the line to save others, but his biggest contribution to the story aside from uniting the Greenes and Rick's group was to highlight what a monster Shane truly had become. Ironically, Shane's choice to murder Otis was likely one of the major catalysts for Shane's ultimate destruction.
Tomas - 2 Episodes
The prison is one of the most iconic locales in TWD history, and although Rick's dream of a safe and secure place for the group to live was admirable, it shouldn't have been shocking that they ran into some unsavory folks along the way.
The least appealing of all the prison inmates was Tomas. While some of the prisoners managed to become genuine members of the group, Tomas was obviously dangerous from the jump, and his actions had long-lasting effects on the story as a whole.
Edwin Jenner - 2 Episodes
Way back in season 1 when the survivors that followed Rick hadn't given up on the old world, getting to the CDC was their ultimate goal. It seemed like when they finally made it to the CDC facility, there was some hope.
But things were not as they seemed, and the doctor who the group believed could save them and possibly save the world was a fraud. Edwin Jenner let the group into the facility, but with the intention of letting them all die when said facility self-destructed.
Dawn Lerner - 3 Episodes
Dawn was undoubtedly one of the strangest and most unique antagonists that the group ever encountered. She was a police officer running Grady Memorial Hospital, and while her responsibilities could explain some of her severity, it's obvious that her sense of morality had been badly warped.
Although her biggest influence on the broader series obviously came when she murdered Beth Greene, she and her crew offered insight into an incredibly unusual facet of what people can and were capable of in order to survive in the best and worst ways.
Sherry - 3 Episodes
It's actually shocking to realize that Sherry only appeared on three episodes of the series given that her character had such a massive impact on the story at large.
She and Dwight give Daryl his first insights into the Saviors when he runs into them in the burned-out woods, and although Sherry and Dwight initially seem to be willing to do anything to stay alive, even if that means returning to the Saviors, ultimately Sherry decides that anything is better than the life she's living with Negan.
Gareth - 4 Episodes
After The Governor returns and destroys the prison community that Rick and the group have built, they're left scattered and hopeless. Hopeless, that is, until the oasis of Terminus becomes the goal for the disparate squad.
But, in typical Walking Dead fashion, this oasis is a mirage, and Terminus is in fact an organized unit of cannibals. Out of all of these man-eaters, the calm and collected Gareth who seemed to think that cannibalism was downright banal made the strongest impression, and becoming a memorable villain in a world as brutal as The Walking Dead, in four episodes no less, is quite the accomplishment.
Joe - 4 Episodes
Of all of the people for Daryl Dixon to run into, the Claimers were likely one of the worst possible options. Their leader, Joe, seemed to be a brutal if pragmatic person at the start.
However, beneath that relaxed attitude was a fairly sadistic and frightening man. When the Claimers attacked Rick, Michonne, and Carl, Joe at least got one of the most memorable deaths in the show's history when Rick literally ripped Joe's neck out with his teeth.
Mika Samuels - 6 Episodes
Obviously when it comes to the storyline with Lizzie and Mika Samuels, Lizzie was really the star of the show, both in terms of the narrative and overall screen time.
However, Mika was an essential part of the story as well, and the heartbreaking realization of what Lizzie had done to her as well as Carol's realization that Lizzie wasn't cut out to survive in this world became one of the most memorable storylines in Walking Dead history.