Ensemble Dark Horse in this franchise.
Avatar: The Last Airbender
- King Bumi, for being a powerful earthbender, his fun personality, and for being one of the few people who Aang knew before being frozen.
- Shyu, the Fire Sage who helps out Team Avatar, proved to be rather well-liked by fans, for being the Token Good Teammate of the Fire Sages, as well as being the grandson of Avatar Roku's firebending instructor.
- Jet was originally supposed to be a one-off character in Book 1, but thanks to being a sympathetic Anti-Villain and a Badass Normal, he ended up becoming so popular that the writers brought him back for the latter half Book 2 as a recurring character.
- There's also June, a Badass Normal Bounty Hunter, who, in spite of only appearing in one episode, became rather popular with fans, which the creators even commented on. This is likely why she reappears in the Grand Finale.
- Although it's not exactly as much "popular" as "well-remembered", Koh, the Face Stealer. He barely had any plot-importance even the two times you see him (one was a flashback), but he's just so damn creepy that he's become a frequenter of fanworks and Epileptic Trees all the way up to the end of the show.
- Ty Lee isn't really as important or developed as her friends Azula and Mai, but she's loved by the fans for her unique ability, tension with Sokka, Genki Girl personality, and cute design.
- Huu, the old man living in the swamp, is rather well-liked by fans for his Cool Old Guy personality, his awesome swamp monster disguise, and his role during the invasion on the Fire Nation.
- The Big Bad Hippo, one of the contestants in the Earthbending tournament Toph participates in, became popular with fans for being a Mighty Glacier with Hulk Speak. It's likely for this reason that he ends up returning alongside the Boulder to help out during the invasion on the Fire Nation.
- Jin only appeared in one episode in Book 2, where she went on a date with Zuko. In spite of this, thanks to her cute design, Nice Girl personality, and status as someone to ship Zuko with, she ended up becoming rather popular.
- Piandao is this, for being a Badass Normal Master Swordsman who once defeated a hundred Fire Nation soldiers.
- Cowardly Lion Nonen and his daughter Kiyi (who have interesting history and dynamics with two main characters), the Crouching Moron, Hidden Badass Big, Thin, Short Trio who Toph trains in metal-bending and the benevolent Eldritch Abomination the Mother of Faces are all beloved characters with only a relatively few comic appearances.
The Legend of Korra
- Jinora became this thanks to being a Badass Adorable Bookworm with similarities to Aang, resulting in her becoming a Breakout Character from Book 2 onwards.
- While the two never became as important to the story as their older sister did, Ikki and Meelo are still this thanks to being two of the funniest characters on the show.
- The Lieutenant, in spite of his lack of screen time and rare chances to speak, proved popular with fans for being a Badass Normal with some cool fight scenes.
- Shiro Shinobi, the Pro-Bending announcer, proved popular for being a Large-Ham Announcer, a Determinator when it comes to reporting things, and his role as the narrator for the series' Opening Narration.
- Tahno, in spite of initially being a jerkass, ended up getting a lot of fans for his attractive design and for Taking a Level in Kindness after losing his bending.
- General Iroh is only given a major role in the Book 1 finale, but proved to be popular with fans for being Zuko's grandson, a Four-Star Badass, being named after Iroh, and being voiced by Dante Basco.
- Zhu-Li barely says a word throughout the entirety of Book 2, yet still became very well-liked by the fans for being The Comically Serious and the assistant to the equally popular Varrick. It's probably for this reason that she saw an expanded role in Book 4.
- The Aye-Aye Spirit, in spite of being a misanthropic jerkass, is popular with fans for his friendship with Wan, as well as having some of the funniest moments of the "Beginnings" two-parter.
- The Carrot Spirit, a minor background spirit from the "Beginnings" two-parter, saw a surprising amount of love from the fanbase for his unique and funny design.
- The dark spirit Bumi ends up pacifying with his flute became well-liked by fans for just how utterly adorable it is.
- Ghazan and Ming-Hua don't get much time to shine in comparison to their fellow Red Lotus members, Zaheer and P'li. Still, the former's Affably Evil personality and status as a lavabender, and the latter's status as a Handicapped Badass Dark Action Girl, has resulted in the two becoming rather popular with fans.
- Opal proved extremely popular with fans for her cute design, Nice Girl personality, and relationship with Bolin.
- The frog-squirrel that appears in "The Coronation" is well-liked by fans for its strange yet cute design.
- Fire Lord Izumi gets a total of one scene in the entire series, yet is still very popular with fans for being Zuko's daughter, as well as a Reasonable Authority Figure who's clearly learned from the mistakes of past Fire Lords.
