Due to the series' having a tendency to introduce new characters every other game until the Unleashed era, Sonic the Hedgehog has many characters that can be considered Ensemble Dark Horse by different sorts of fans. While they may have even been main characters in their debut games, they quickly fall to the side, leaving them to acquire fanbases of their own.
- Surprisingly, Big the Cat has fallen into this after so long of being The Scrappy, in a similar vein to Waluigi. Aside of being consistently better-received than he was upon his debut, even that has led to memes about how he's clearly everyone's favorite character, as well as being responsible for some of the funniest moments from Lets Plays of the game, such as the Game Grumps and The Runaway Guys. Sega of Virgin Islands even gave Big his own game, and he even got his own LEGO Dimensions scenarios.
- Mighty the Armadillo and Ray the Squirrel got to appear on posters in Sonic Generations and are popular thanks to the Archie comics, even though, up until 2018, Ray only appeared in one game (SegaSonic the Hedgehog) and Mighty in two (SegaSonic the Hedgehog and Knuckles Chaotix). Needless to say, fans lost it when the duo made a surprise return in Sonic Mania Plus.
- In another corner of the fandom, a great deal of prominence has been given to Honey the Cat, an extraordinarily detailed character who was Dummied Out of Sonic the Fighters. This may have motivated Sega's decision to promote her to playable in the 2012 'Xbox Live Arcade & PlayStation Network Updated Re-release. She also got a lot of screentime in the Shattered World saga during the Archie Comic's last major run.
- Ever since Sonic Colors, the Cyan Wisp became popular with fans. This is for a number of reasons; it being one of the first introduced, their design as a suitably squishy load of squids and because his color power is both fun to use and capable of triggering helpful glitches while speedrunning.