Foreign Dittos are a great way to increase your chances of hatching a Shiny Pokemon but how exactly do you get them? You can only get this Pokemon from a Pokemon copy that has a different language than the one you are currently playing.
How to Get a Ditto
Before you can get a Foreign Ditto, you will be needing both the National Dex and the Poke Radar from the Professor in Sandgem Town. This means that you need to register at least 150 Pokemon in your Sinnoh Pokedex.
After upgrading your Pokedex into the National Mode, go to Route 228. Use your Poke Radar on the grass to get encounter a wild Ditto. After getting a Ditto, you are ready to get a Foreign Ditto.
How to get a Foreign Ditto
Press Y and go to the Global Room. When asked if you want to enter the Global Room, Click on Yes with a Link Code. You can save your progress at this point and enter this code: 44484448.
People who would like to trade a Ditto will be using this code in the Global Room. If you want to check the region of the Ditto, you can press Check Other Pokemon. You can find the region of the Ditto next to its level.