Pokémon Sword and Shield introduced Galarian Forms, you can check them here. One of these forms is Galarian Mr. Mime that evolves into Mr. Rime, an Ice/Psychic very elegant Pokemon with his dashing hat, an ice cane, and a mustache that few would have the courage to grow.
Today you're gonna learn how to get Mr. Rime, but if you're not a mustache fan, we will also teach you how to get the Kanto Mr. Mime.
How to get Mr. Rime in Pokémon Sword and Shield
Trade with a stronger friend!
Or, if you're a loner like me, you have another option. You can only get Mr. Rime by evolving a Galarian Mr. Mime, and to get one Mr. Mime you need to go to Route 10. This can only happen after beating all 8 Sword and Shield Gym Leaders, so it's an endgame content Pokémon, although not legendary. You can find Mr. Mime wandering solely On Route 10 in any grass patch.
Mr. Mime evolves to Mr. Rime at level 42, most likely the one you capture will be at or over the level. Just Candy him and enjoy some tap dancing.
How to Get Kantonian Mr. Mime
First, you need one Obstagoon. The easiest way is to capture one at the Lake of Outrage area. Fly to Route 2 and drive over the lake with your bike and you can find one as soon as you reach land. You can also evolve a Galarian Zigzagoon, but nah, doesn't make sense to have all this work just to give it away. Capturing one is much faster.
Then, go to Route 9 and proceed right to Spikesmouth. This is where you fight, or did, against the leader of the Dark-type Gym, Piers.
If it's your first time there, it will be crowded with members of Team Yell. You'll need to battle some of them before reaching the arena where the Gym Leader is located. After reaching the arena, there is a stand in the upper left corner that looks like a kissing booth. Talk to the pink mohawk dude and he will offer you a trade, your Obstagoon for his Kantonian Mr. Mime. Accept and voila.