Rovio's promising a Christmas edition of Angry Birds, saying it will be offered as a free upgrade to the Halloween version.
The company tweeted on Friday to say that a release date would be dependent on Apple's approval of the app. The game will initially be available for Android and iOS devices only, although Rovio is hinting at a Windows 7 version.
And Finnish website Ylex has pictures, showing birds and pigs alike wearing Santa hats and a barrier of Christmas trees through which which the angry birds have to smash in order to reach their porcine enemies. New levels have also been added.
Rovio looks to be aiming to capitalise on the success of the game with a series of merchandising spin-offs. The company's already marketing Angry Birds plush toys, due to go on sale in December, for $14.99.
Last week, the Daily Telegraph reported that Rovio is planninng versions of the game for the PS3, Xbox 360 and Wii, and the company is also reported to be working on a Facebook edition. There have even been rumors of a movie.
Angry Birds has become one of the App Store's best-selling apps, with more than 13 million downloads of the free version of the game, plus another seven million paid-for downloads.