Birdo Eggs are projectile eggs spat out of the mouths of Birdos as a means of attack. They can be plain white, but have also been shown to have pink spots in some appearances. Also, in various videogames, the Birdo Egg appears as the Birdo emblem. This eggs made their first appearance in the American release of Super Mario Bros. 2 (and in the Japanese-only game, Doki Doki Panic that it is based on). Here, Birdo Eggs were plain white and were spat by Birdo at her adversaries, Mario, Luigi, Princess Toadstool and Toad, who would lose a life if they were hit. In some levels, the only way to damage Birdo was to pick up her eggs and throw them back at her.
In the remake, Super Mario Advance, in addition to a reappearance of normal Birdo Eggs, a giant variety shot by Robirdo was introduced. Apart from their size, they behaved exacly like normal Birdo Eggs: they could cause damage to the protagonists; or be ridden, picked up and thrown back at their sender to do damage to it instead. In Super Mario RPG: Legend of the Seven Stars, a Birdo hatched from a giant white egg known as Shelly. Birdo could speak to Mario through the eggshell, and requested a battle with him and his partners, and their attacks eventually split the egg open. Now hatched, the Birdo could attack Mario and the others with explosive Eggberts, rather than normal Birdo Eggs.
In Super Mario RPG: Legend of the Seven Stars, a Birdo hatched from a giant white egg known as Shelly. Birdo could speak to Mario through the eggshell, and requested a battle with him and his partners, and their attacks eventually split the egg open. Now hatched, the Birdo could attack Mario and the others with explosive Eggberts, rather than normal Birdo Eggs.
In Mario Kart: Double Dash!!, Birdo appeared as a playable character, and her Special Items are Birdo Eggs. They behave the same as Birdo's counterpart, Yoshi's eggs, differing only in that they are covered in pink spots (Yoshi's are green). Once thrown, the eggs home in on the nearest character above Birdo and her racing partner in rank. Upon collision, the Birdo Egg breaks and releases three items at random, and the kart that was hit flips over. These items can include Bob-ombs, Stars, Mushrooms, Red or Green Shells, Fake Item Boxes, or Bananas. Birdo eggs will also break if they hit stray Bananas or Shells, or environmental hazards, and if they go long enough without hitting anything, they will self-destruct.
In Mario Party DS, a Birdo Egg appears as a card in the minigame Memory Mash. These looked the same as in Mario Kart: Double Dash!!, as Yoshi Eggs with pink spots instead of green. In Mario Super Sluggers, a Birdo Egg appears Birdo's Batting special move Cannon Swing, where she spit out an egg with pink bows printed on it. Then Birdo slams the egg with her bat, so hitting the baseball thrown by the pitcher, which breaks the egg. Meanwhile, the baseball goes with amazing power forwards, so hitting the pitcher. In this game, the appearance of the Birdo Egg also changed; from a pink spot pattern to a pink ribbon pattern depicting Birdo. Also, in Captain Rainbow, large, pink-spotted Birdo Eggs can be seen mounted on either side of her Cute Home.