The details of the two-part Halloween 2021 event in Pokémon GO have now been released by Niantic. In addition to releasing Shiny Spinarak, Pumpkaboo, Phantump, Mega Absol, and Galarian Slowking, this event will also bring a brand-new mechanic into Pokémon GO: the size mechanic.
The new size mechanic in Pokémon GO will be tied to the release of Pumpkaboo and its evolution Gourgeist. Here's what Niantic has to say about this upcoming mechanic in the game:
With the introduction of Pumpkaboo comes a new mechanic to Pokémon GO: Pumpkaboo that are larger will actually look larger in the game!
Both Pumpkaboo and Gourgeist will be available in:
- Small Size
- Average Size
- Large Size
- Super Size
It seems as if these will be treated as different Formes in the Pokedex, as these Pokémon look noticeably different in the game. What makes me think that these will be treated as Formes unlike visible Gender differences in the game is the following bit of information from the blog:
In celebration of Pumpkaboo's debut and the mechanic it introduces, a Collection Challenge will be available that requires you to collect Pumpkaboo of various sizes.
Niantic further explains the inspiration behind this new mechanic in their description of the event, which references the Pokémon X & Y games that introduced this aspect of Pumpkaboo and Gourgeist in the originals. Niantic writes:
The second part of Pokémon GO Halloween Mischief is called Ghoulish Pals! Ghost types will be appearing more often everywhere as we get closer and closer to Halloween. The spectacularly spectral Pumpkaboo and Phantump will make their Pokémon GO debuts, alongside their Evolutions, Gourgeist and Trevenant! We're also getting word that you'll be able to encounter Pumpkaboo of varying sizes, just like you can in the Kalos region. Gourgeist evolved from Pumpkaboo will also vary in size! During this time, intrepid Trainers can complete a Collection Challenge that'll encourage them to seek these Ghost-type Pokémon!