Monster Hunter License

 a limited-time premium consumable released on October 3, 2018 for the Treehouse of Horror XXIX Event. It the amount of currencies received from tapping Monster Minions in friends' towns. Once purchased, its benefits until the end of the event.

Trivia

 * Doubling the rewards from neighbors' town, the player daily get a maximum of 2100 Fangs / Fur / Wraps, instead of the usual 1050 (maximum of 10 towns multiplied by 3 Monster Minions per town and 35 pieces of the currency, 70 pieces respectively).
 * For 14 days, the duration of each act, it an addition of up to 14700 prize track currency.