At the present time, there is only one exclusive Detective Pikachu Amiibo on the market. This is far less than most other Nintendo Video Games, but this one Amiibo is crucial to have if you happened to miss some of the Pika Prompts during the game. You see, by obtaining the Detective Pikachu Amiibo and using it after completing the Main Story, you will unlock every last Pika Prompt, and permanently no less. This is great to have if, as mentioned, you accidentally missed obtaining one of the Pika Prompts during the main gameplay and don't want to repeat an entire chapter to obtain it.