Last week, Pokémon Go received a huge update that overhauled gyms. Thanks to the update, gym owners could feed their Pokémon berries to keep them motivated. Conversely, rivals could chip away motivation with repeated attacks. This update certainly gave new life to the once-popular title, but it also allowed for something unexpected (and awesome) — themed gyms.
As pointed out by Kotaku, prior to this update, Pokémon gyms would be defended by armies of top-tier pocket monsters. Now, because of the “motivation” mechanic, even low-tier Pokémon can successfully defend gyms. Since high-level Pokémon are no longer required to defend one’s gym, players are free to have lower-tier Pokémon as defenders. This makes it possible to have gyms filled with specific types of monsters.
Folks around the internet have posted some of their themed gyms on social media. The most popular type of themed gyms are ones composed of Eevee Pokémon. There are other evolution-type gyms, and even baby Pokemon gyms.