King Pig Smooth Cheeks (or simply King Pig) is the main antagonist of the Angry Birds series. He is a comically obese pig. He is the current king of Pig City and serves as the leader of the Bad Piggies. He is passionate about eating three unhatched eggs that belong to a flock of flightless birds, so he continually orders his subjects to try and steal these eggs for him. Unlike the great Piggy Kings of the past, King Pig has never eaten a single egg in his life. Most pigs think he does eat eggs since he is already very portly. King Pig is terrified that if the other piggies found out he never ate any eggs, they will force him off the throne. King Pig has succeeded in stealing the eggs most times, but he is always caught by the birds, leading to him and his subjects to get popped, though Angry Birds: Slingshot Stories shows that this does not give them any harm. King Pig is the son of former king Leonard Mudbeard, who ruled long before the events of Angry Birds.

King Pig seems to be young in mind, having to sleep with the assistance of hearing storytelling, and crying a lot. He once had a brief relationship and marriage with a cabbage and accidentally went insane, but he ended up eating it.

More facts here: https://angrybirds.fandom.com/wiki/King_Pig_(character)#Current_Toons_Style