In 2018 and 2019, Professor Willow offered us a few special quests to get Spiritomb. These were concentrated around the number 108 to mark the fact that Spiritomb is itself composed of 108 spirits and that his entry into the Pokédex of Sinnoh is none other than the number 108.
Many players didn't have the chance to do these quests in 2018 and, unfortunately, this is the only way to get Spiritomb to date. Luckily, "A Spooky Message" is coming back for Halloween 2019 and we hope it will be the case in 2020.
A Spooky Message 1/3
- Catch 10 Ghost-type Pokémon (Reward: Haunter encounter)
- Make 8 great throws (Reward: 1080 XP)
- Use 108 berries to help you catch Pokémon (Reward: you encounter a random Pokémon but most often it's Lickitung)
Tip: For berries, you can feed a Pokémon and run away.
A Spooky message 2/3
- Catch 10 Dark Pokemon - (Reward: You encounter a random Pokémon)
- Spin 8 Pokestops you've never visited before - (Reward: 1080 XP)
- Captures 108 Pokemon - (Reward: you meet Spiritomb)
A Spooky message 3/3
No new tasks are actually present. You captured Spiritomb in step 2 and this step 3 is only used to give you extra bonuses. You will then get 3 times 1080 XP points. You will also get 18 Spiritomb candies and 1080 stardust.
