Season's Greedings

Season's Greedings is the second holiday-themed episode of Angry Birds, released as part of Angry Birds Seasons. It was released on December 1, 2010. This is Christmas-themed episode. Users who downloaded the separate Halloween levels released earlier were given the Season's Greedings levels as a free upgrade.

Season's Greedings is the unique as it contains 25 levels, which opened once per day (At the time of its release), advent calendar style. Because of this format, the player can't unlock additional levels by completing them in order like in other episodes. Thus, the levels can be tackled in any order the player desires, proving that the required levels were passed. To open the levels, the player must have a wireless internet connection. By default, the level is locked, and if the player attempts to access it when not connected to the internet, he/she'll be presented with an error message. But should the player connect successfully to the Internet before opening the levels, they'll load the level and will never encounter the problem again. Rovio has stated that an update would be released following Christmas Day 2010, when the twenty fifth and final level was released, which would open all of Season's Greeding's levels, but even after the Hogs and Kisses update was released in February 2011, error messages can still be received.

Storyline
The following is from The World of Angry Birds Official Guide, as told by the Mighty Eagle:

YULETIDE GLEE

Red and the Blues must have been going soft. There they were taking the eggs on a sleigh ride in the Crown Mountains when they were met by pigs bearing gifts. Full of the holiday spirit, bird and pig sat together watching the sun come up — until the seasonal swine slid away with the eggs. Those rotters!

Golden Eggs

 * In level 13, smash the wreath in the center of the structure to obtain a Golden Egg.
 * Earn three stars on all 25 levels to unlock the "Big Present" Golden Egg.

Bonus levels:
 * 1) Contains 2 yellow birds and 1 blue bird.
 * 2) Contains 1 red, black, white, boomerang and yellow bird.
 * 3) Contains 3 big brother birds.

Trivia

 * This episode also is the only one so far without any ending cutscenes or pictures. It does, however, include an ending video.
 * One can unlock the achievement for completing this episode and the Special Item, the Present with no star just by completing Level 25, even if not all of the other levels have been completed. This also happens with Wreck the Halls and its Special Item, the Candy Cane with no star.
 * The title of this episode is a play on the phrase, "Season's Greetings".
 * This is the first episode based on Christmas, the second one being Wreck the Halls, the third one being Winter Wonderham and the fourth being Arctic Eggspedition.
 * The episodes Trick or Treat and Ham'o'ween are the second pair of main theme - Ham'o'ween.
 * Some of the levels as they appear in differ from the main version of Seasons. Some levels have minor changes, such as additional birds. But others, such as Level 5, are completely different.
 * On Level 18, 4 pigs wear hardhats from The Big Setup.
 * If the player go to the ending credits in ver. 1.1.0 (Season Greedings update) after going to a level of the previous episode, Trick or Treat, the images will be the original images of the first game instead of images featuring birds and pigs in festivity
 * The King Pig appears four times in this episode: in level 1-6, level 1-25, and in both Golden Egg levels.
 * When Season's Greedings was updated in Angry Birds Halloween, that update changed the name to Angry Birds Seasons for first time.
 * This episode is the first episode in the Angry Birds series to be located in snow.