Here you can find spawners for custom maps. They are useful both for modders that want their creatures to spawn on map X, and for server administrators that want to see which available spawners map X have for them to manipulate and populate.
Take note that these spawners are provided as-is. They’ve been sent to me and can be publicly shared. It’s always up to the mapmaker to make sure that these works and are up to date.
You can download the spawners as an archive over a GitHub by either using the GitHub desktop application or using the website GUI(clone/download as .zip). After you’ve downloaded them, place them directly in your Mods folder. Make sure they keep the exact same folder hierarchy or they won’t work properly. Example below,