Booma

Energy Balls are objects in Angry Birds Star Wars 2. They are used to destroy strong structures easily. They are mostly indestructible, but needs momentum to break blocks. They are mostly seen on Catapults, at will be launched when hit by a bird or block.

In Star Wars
The energy balls are from a scene in the Star Wars Film The Phantom Menace, during the Battle with the Gungans and Battle Droids. However, in the Angry Birds game itself, there are energy balls outside the battle.