If you thought the only Kanto Meowth in Pokémon Sword and Shield was the Gigantamax Meowth you could get for purchasing the game, then think again. There is another Kanto Meowth hidden in the game, and it can also evolve into a Persian.
The special Kanto Meowth won’t appear in the overworld, and you cannot catch it. Instead, you must trade for it with an NPC. The only way to get the Kanto Meowth is to talk to a boy in the very first gym in Turffield. You will find him in the first gym where you take on Milo, wearing a blue sweater.
He will trade you the Kanto Meowth as long as you are willing to give him a Galarian Meowth. These are a pretty common spawn in the Wild Area when you first arrive in it. Agree to the trade and you will see a brief animation, and will then be the proud owner of a Kanto Meowth.
When you get the Kanto Meowth, put it in your party and level it to 28, and it will evolve into a Persian. You also cannot breed the Kanto Meowth; this is the only way to get the Kanto Meowth in the game. If you breed the Kanto Meowth, then only Galarian Meowths will spawn from the eggs.
Once you have gone through the process of evolving your Kanto Meowth into Persian, you will be one step closer to filling your Pokédex.