Mighty Hoax

Mighty Hoax is the second episode of Angry Birds, which contains two themes with 21 levels each. Much like it's preceding episode, it takes place once again in the vast plans, where after recovering from his tribe's defeat, the King Pig once again steals the Bird's eggs, replacing them with cardboard cutouts of the eggs. The Birds discover this, and once again release their vengeance on the Pigs in order to retrieve their eggs after being taken from them the second time.

When the Birds complete Theme 4-21, they discover the King they defeated is in fact a cardboard cutout, and that the real King is still out there. Later, the Birds finally succeed after destroying another cardboard cutout in Theme 5-21 and retrieve the eggs. The real King retreats while the birds celebrate their temporary victory.

Trivia

 * This is the only known episode to have more than one King Pig due to the concept of the King distracting Birds with cardboard cutouts of himself.
 * In contrast, this is also the only episode where the King escapes without injury rather than getting brutally beaten by the Birds.
 * This is the final episode to contain 21 levels per theme.