Glitches

A glitch is an error in a game in which something happens that the game makers did not intend to make happen. Also called bugs and easter eggs.

List of Glitches
Here is the list of glitches found in Angry Birds.

Corpse Glitch
Prerequisites: Yellow Bird or Boomerang Bird unlocked

How to: Fire a Yellow or Boomerand bird into the air while using its ability. Then, fire a second bird (this one can be any bird) so it hits the first bird with the ability. If done correctly, a yellow bird will have its "speeding" sprite replacing its Corpse sprite, and the boomerang bird will have its mouth wide open as if it's flying in the air.

Notes: Explanation: The game makers programmed a bird to enter its corpse sprite if it hit the ground, pigs, blocks, other birds, etc. They, however, probably forgot to progam the system when a bird using its ability hits a flying bird, thus leaving the bird "frozen", until it disintegrates.
 * The glitched bird will disappear after left immobilized, just like any other corpse, but will make pain noises and such.

White Bird Glitch
Prerequisites: White Bird unlocked

How to: Fire the white bird and use its egg-shooting ability. Angle the bird so that it will hit a piece of ground (indestructable material). There is a slight chance of the white bird swelling up as if it didn't fire the egg.