Tuxemon uses the Tiled map editor to create all of the maps seen in the game. With Tiled, you can load multiple tileset images which contain various tiles that can be used in your maps. A tileset image can be *any* size, as long as the individual tiles themselves are 16 x 16 pixels in size.
Here is what a whole tileset image might look like:
Using your tilesets in Tuxemon
You can use your tilesets in Tuxemon by simply placing your tileset images in `resources/gfx/tilesets` and then adding your tileset to a map using the Tiled map editor. For more information on how to add your tileset to map, take a look at the Creating Maps page.