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 Pigs are also appears in Angry Birds Epic but different appearence.
 * Necromancer Pig's hat looks like a viking's hat due to it's horns, although the hat doesn't look like a viking hat at all.
 * Also, viking hats are not horned. They were given this shape for an opera made by Richard Wagner, a famous classical composer. There is also no evidence of horned viking hats in archeology.