For a series with a huge cast, we'll do our best. UNMARKED SPOILERS AHEAD, FOR THE MOST PART! Also, ever-changing. This series is still going on.
- Review Teamnote Sir Cinemacus, Z-Squared, Shadow-Squared, Godzilla 2000, Finn, Twilight Sparkle, Marceline, Mothra, Basil, Fluttershy, Megatron, Discord, Mr. Freeze, Z-Squared's Pets, Starscream, Squidward, Gwonam, Doc, Tafeli, Robo-Lincoln, Lady Liberbot, Xander Cruise, Drogon, Eric Feeble
- Court of Ahnilnote Ahnil, Ro-Man, Snippit I, Nitocris, Bagan, Time-Frame, Killface, Valeena, Jay Sherman, Alternate New York
- Monster Island Inhabitantsnote Anguirus, Rodan, Gorosaurus, King Caesar, Manda, Varan, Baragon, Minya, Ebirah, Fairy Mothra, Kiryu
- Equestrian Inhabitantsnote Rainbow Dash, Pinkie Pie, Rarity, Applejack, Rick, Vergil, Azazel, Thundercracker, Keep-Away Island Residents, Sharko, Sea Inhabitants, Smarty Smarts and Octocat, Titanosaurus, Hatchiyack
- Elmore Inhabitantsnote Gumball Watterson, Darwin Watterson, Anais Watterson, Nicole Watterson, Meta-Ridley, Firefly, V, Ian, Barricade, Sky-Byte, M.O.G.U.E.R.A, Mother Brain
- Other Characters Season 1 to 3note Kronos, Nemesis Decepticons, Queen Tyr'Rhanee, Nessie, Flapjack's Family, Sea Monsters, Metal Gear RAY, Hunston Abadeer, Amy and friends, Ice King, Alternate Los Angeles Residents, The Goodfeathers, Martian Soundwave, Alopex, Babylon Gardens Inhabitants, Heart and Umasou, Egg Island Inhabitants, Quetzalcoatl, Nekku
- Major Villainsnote Necrosan/Sin, Golus, Colonel Kernal, Chi-Chi, Alternate Twilight, The Legendary Kaiju/Destiny, Transformed Housepets, Bagan, Dogolas, Destroyah, Nightmareus
- Hell Inhabitantsnote Satan, Lucifer, Faust, Oblivion, Beelzebub, Kumasogami, The Disciples of Satan, Fleshsaurs, Legion of Musicians, The Seven Deadly Sins, Scanty and Kneesocks, Monster X
- S.I.C.Onote Dr. Siek, Thaeledus, Dr. Bitch Spasms, Kayla and the Emerus Tribe, Micheal Stevens/Manimal, Scourge, Buzzsaw, The Terrorcons, Cesare/A.P.E.X, King Dedede, Katai
- Alternate Equestrianote Alternate Mane Six, Alternate Spike, Kalameet, Drocsid
- F.I.S.Tnote Sixshot, Swelter and Glacius, Circe, Visceral, Phil
- Psyconic's Rebellionnote Psyconic, Screwball, Demolisher, Tagoma, Sorbet, Garble, Gilda, Guilala
- Other Villains Season One to Threenote Voodoo Justin, Dr. Caligari, Nosferatu, Dracula, Manos, Gigan, Lycos, Snippit, Kal-Roh, Clear-Teeth Jones/Islandra, Con Rit, Titan and his Minions, Megalon
- Bonus Charactersnote Gojira, Draco, Erode, Triple-6, The Gogmazios