As of right now, the new Loot Goblin amiibo has finally released for the Nintendo Switch! You can get yours by heading over to Gamestop. Here's what they do, and how they work:
Originally Posted by Nevalistis (Official Post)
In order to scan an an amiibo, first you’ll need to open an amiibo Portal. By default, all characters have an amiibo Portal item available to them in their stash. Activate this item from your inventory to open a Rainbow Portal.
Scanning the Loot Goblin amiibo will transform this Rainbow Portal into a shimmering golden portal that will take you to The Vault—the mysterious and treasure-filled realm of the Treasure Goblins and their enigmatic Baroness, Greed.
Scanning any other amiibo can only be done outside of town and will spawn a Champion pack of enemies—a challenging group of monsters with special powers and improved treasure.
All amiibo can be scanned once per day each, so be sure to take advantage of those extra challenges, loot, and first-class ticket to The Vault as often as you can!