Halloween is fast approaching, and Niantic's augmented reality (AR) game "Pokemon Go" is preparing a special Halloween event for players. However, this year's Halloween celebration may not be an ordinary spookfest, as there are speculations that Niantic is also gearing up for the arrival of Gen 3 pocket monsters.

The new content and quests coming with the "Pokemon Go" Halloween event is all up in the air, as Niantic has only provided promotion teasers for the said event. Although, there are hints that the Halloween event will be a lot more than trick-or-treating, as Gen 3 Ghost-type Pokemon are spotted in the new images from Niantic, GameSpot reported.

The images showing the Gen 3 Pokemon may not be intended for release this soon, although the iOS App Store displayed the photos to entice players to participate in the event. The Ghost-type Pokemon in the teaser images are not yet even introduced in "Pokemon Go," as the roster of pocket monsters in the mobile game is only updated to Gen 2.

The new teaser images posted by Eurogamer show the yet-to-be-revealed Gen 3 Ghost Pokemon such as Duskull and Sableye. Fans who have seen the images are certain that Niantic is cooking up something good for the upcoming Halloween.

To note, rumors about the introduction of Gen 3 Pokemon have been going around for weeks, and the latest Halloween event teasers gave the much-awaited confirmation. Previously, details gathered from a datamine suggest that the Gen 3 monsters will arrive in the game soon. According to Slash Gear, the in-game data prior to the Halloween event is similar to the datamine results when "Pokemon Go" was about to launch Gen 2.

Aside from the underlying clues of Gen 3 Pokemon coming this Halloween, the event teaser also shows Pikachu wearing a witch hat. The Halloween-themed Pokemon will be around the game once the event officially starts. The upcoming event will be the second Halloween celebration since "Pokemon Go" launched in 2016. Last year's event featured the ghostly Pokemon such as Haunter, Drowzee and Gastly, which appeared more often throughout the event.