Boy and Girl Eggs

The Boy and Girl Eggs appear only in the Hogs and Kisses episode of Angry Birds Seasons (2011). Little is known about them. The Boy Egg wears a baseball cap and the Girl Egg has a bow on the top of her shell. They are both seen in artwork with the Female Red and Female White Birds, but appear with the Female and Male Red Birds in the final art for the episode.

The Girl Egg can be seen in the game on the far right in level 1-15 of Hogs and Kisses.

Story
The artwork shows a pig stealing the Girl Egg in a net while the Boy Egg looks on. The final artwork when a player completes all 15 levels of the Hogs and Kisses episode shows the eggs reunited while the male and female Red Birds look over them both, implying they may be the Red Bird's offspring.

Trivia

 * These are two of the few eggs shown to have any sentience in any of the Angry Birds games or artwork. For more examples, see the "Umbrella Egg" in Angry Birds Seasons: Cherry Blossom and the "Antenna Egg" from Angry Birds Space.