Pokémon GO is embracing the Halloween spirit once again, this time with a few treats in the form of pocket monsters from the series’ third generation of games (Ruby, Sapphire, Emerald) that were leaked during the week.

The mobile game’s Twitter account officially confirmed the Ghost and Dark type-heavy event featuring Pokémon GO debuts for Banette, Dusclops, Duskull, Sableye and Shuppet on Oct 20. A costumed Pikachu, wearing a witch hat, also makes a first appearance, joins the lineup that previously included Drowzee, Gengar, Ghastly, Golbat, Haunter, Hypno and Zubat.

Gastly and Cubone are back again for #PokemonGOHalloween, and this time, they’re bringing a few friends… https://t.co/UANQTkulVS pic.twitter.com/gP5OU1v6oR

— Pokémon GO (@PokemonGoApp) October 19, 2017

Evidence of the event and the arrival of third generation Pokémon was first posted by Reddit community The Silph Road. An image of a Halloween splash screen was uploaded along with notes on sound files for Halloween music and additional Pokémon cries from the Ruby/Sapphire/Emerald era up to Deoxys. Fans of the original generation may recognize the Lavender Town theme The Silph Road claims to have datamined, a tune central to an urban legend.

Other Halloween related features include an increase in Candy, a necessary item for evolving and powering up Pokémon. Candy will be doubled when catching, hatching and transferring Pokémon in addition to a designated Buddy Pokémon finding the treats twice as fast during the game’s walking portion. Players can also add a festive touch to their avatars with a Mimikyu-themed hat, designed after the Disguise Pokémon discovered in Sun and Moon.

While a handful of Pokémon outside the first two generations have made their way to GO, players will have to wait a few months for the complete third generation. The rest of the R/S/E class will gradually arrive in the mobile game starting December.

Pokémon GO‘s Halloween event will run until Nov. 2 and is available for Android and iOS devices. The game first released July 2016 and quickly became a pop culture sensation.