Obols

 a limited-time currency released on October 4, 2016, for the Treehouse of Horror XXVII Event. They are the only currency used to craft prizes in the event.

They can be obtained:
 * By tapping Feral Monsters that spawn in the player's town, with a 10% chance of being dropped.
 * By completing event themed Daily Challenges.
 * In packages from personal prizes.

Packages
Packs containing different amounts could be obtained as prizes:

Gallery
US$