If we’re going to allow Guardians of Pondonia images here, it’s important to know that it’s not directly related to My Little Pony. Despite what some might believe, it’s intended as a parody of MLP rather than a fan work, which also means Athena isn’t technically an OC. Therefore, I feel like it would be best to have all Guardians of Pondonia images tagged as “parody.” Alternatively, you could go the Them’s Fightin’ Herds route and tag them as “community related”, though I’m not sure if Shawn Keller has identified himself as a member of the fandom.