In order to obtain Galarian Slowking, you will need to have a Galarica Wreath. This wreath can be created using 15 Galarica Twigs, which can be found scattered around the Isle of Armor and Crown Tundra. Once you have the twigs, head for the Roaring-Sea Caves in the central eastern part of the Crown Tundra. You can reach it by traveling to Giant’s Foot east of Giant’s Bed. From there use your bicycle to follow the river into a cavern. Head through the cavern to reach the Frigid Sea. Follow the water left through a narrow canal to reach a secluded cave where you will find an elderly lady who will create the wreath for you. Use the Galarica Wreath on a Galarian Slowpoke to evolve it into the Galarian Slowking!