They will fire yellow apples at any incoming birds.
When their target is locked, they will shoot.
Sometimes, a cannon could lock target too early and miss the bird. This happens when you shoot the bird in a familiar way or if you get your bird behind an object. Thus the yellow apple can't go through the object.
Cannons are auto controlled, they will aim and shoot even if the pig isn't in the machine that the Cannon is attatched to.
It is always recommended to destroy Cannons to bring down a pigs' defense.
They are first seen in Egg Defender-9.
The purpose for pigs to have Cannons attatched to their machine is so they could stop birds at long ranges.
* - Episode is in Classic World in the Chinese version • ** - Episode is in New World in the Chinese version • † - Indicates unused content • - Indicates exclusivity to the Chinese version • - Indicates exclusivity to Angry Birds Time Travel • - Indicates exclusivity to the Kakao version • - Indicates exclusivity to the version of Classic in Angry Birds Trilogy