Necromancer Pig

Necromancer Pigs (known in social media as Necro Pigs) are special bonus pigs in Angry Birds Stella.

Strategy
He will start to sing in the levels, causing pigs to turn into cursed pigs and when the pigs are defeated, they will rise from the ground, as the Zombie Pigs, which give a new wave of pigs to the player defeat, defeating Necromancer Pig will prevent him from casting the curse.

Trivia

 * The Necromancer Pig also appears in Angry Birds Epic but with a different appearance.
 * Necromancer Pig's hat looks like a Viking's hat due to its horns, although the hat doesn't look like a Viking hat at all.