Darth Sidious

Darth Sidious (sometimes called Emperor Palpatine) is King Pig as the secondary antagonist and appears in Angry Birds Star Wars and Angry Birds Star Wars II.

Angry Birds Star Wars
Darth Sidious appears as the last boss. After hitting him with some birds, he will be very injured and stunned. After that the player can play as Darth Vader, who's the only bird who can defeat Darth Sidious.

Angry Birds Star Wars Facebook
Darth Sidious only appears in tournament levels as a hologram in the game. His power is to hit objects and enemies with chain lightning.

Angry Birds Star Wars II
In the second game, he becomes a playable character and is also seen more frequently. The electricity he shoots can conduct through Iron, usually destroying surrounding blocks hit with electricity.

Sidious wore a false beak while he was disguising as a good old bird and working as a chancellor. The Jedi Birds and their fellow were totally unaware with Sidious' true identity as a ruthless, greedy Sith Lord.