Pokémon Go will host its second annual Halloween Event Oct. 20 through Nov. 2, and it marks the start of a progressive rollout of Gen 3 monsters. Niantic announced the development in a blog post Thursday morning.

Just like last year, Pokémon Go’s Halloween festivities will revolve around seeing more of your favorite ghost-type Pokémon like Ghastly and Gengar. New to the party for 2017, however, are Ruby And Sapphire favorites like Sableye and Banette. That being said, unlike some fans had assumed given recent data mines, not all Gen 3 Pokémon will be available at once. Instead, the rest of that classic set will be gradually added to the game through December.

Also new is the addition of a Witch Hat Pikachu to add to your expanding collection of holiday-themed rodents. Avatar customization will also be fleshed out with a Mimikyu’s Disguise Hat clothing option. As if venturing out into the woods to find ghosts wasn’t scary enough, now trainers will be confronted with lots of unexpected virtual encounters while in transit.

In the tradition of seasonal Pokémon Go events like this one, 2017’s Halloween Event also comes with the following perks:

  • Extra candy yield from Buddy Pokémon
  • Doubled Candy yield from catching, hatching and transferring Pokémon
  • Buddy Pokémon will find candy at double speed
  • Special boxes from the in-game shop include Raid Passes and Super Incubators for future adventures

It remains to be seen just how hard to find these new Pokémon will be, but we imagine they’ll likely be pretty plentiful into November considering ghost types are already being favored. Data mines indicate that this event is just the start of what appears to be a full Gen 3 rollout, so we imagine new monsters will be dropping quickly in large amounts once this event concludes. For those who’ve fallen off the Pokémon Go train, now seems like a better time than ever to get back on. As long as you don’t mind the seasonably chilly weather, there’s an absolute ton of reason to return.

While Pokémon Go was majorly expanded through the addition of legendary monsters this summer, it’s been nearly a year since the Gen 2 rollout began in February. Niantic is definitely pacing the arrival of new creatures in a very deliberate way, and that says nothing for the onslaught additional features that could be implemented in the winter and spring months ahead.

Pokémon Go is available now for Android and iOS. The Halloween Event runs Oct. 20 through Nov. 2. Festivities start and end at 3 p.m. EDT.