Hallowe'en is an Event that remembers those who have passed and occurs at the end of October.
Trick or Treat (2014)
The event started on October 30th, and the reward was given out on the 2nd of November. During this event, whenever users would load pages they would occasionally darken and the cursor provided a small glow to help users find the "trick" or "treat." If a user found a "trick", they would find a random Ghost Pokémon and clicking on it would disperse the "darkness" from the screen. If a user found a "treat", they would find one of seven different candies. If all seven were found, they could be exchanged for a Hallowe'en Witch Purrloin.
Spirits Unchained (2017)
The Spirits Unchained event ran for two weeks in 2017, starting October 30th and ending November 12th. During the event, users completed a list of tasks featuring Hallowe'en Witch Purrloin and its evolution, the latter of which was introduced in the event. At its conclusion, the Vampire Line from the original PokéFarm was introduced.