Angryverse/Hektor Porko

Hektor Porko is presumably the mastermind behind the mysterious mirror dimension.

Judging by his apperence, he is probably a hipster.

Angry Birds Space
In Angry Birds Space, he is a pig that was smart enough to create planets and contrations fully of expensive materials, the most special one being brass, which he used to create small planets and spaceships out of it. When King Pig knew about this, he requested Porko to help him in defeating them and he did, but was defeated in the Mirror Worlds, which is accessed by entering a portal found in the Brass Galaxy.

In gameplay, He will be popped with a hit by any bird (except for The Blues, which needs 2 hits to pop him) or by any blocks (except for glass block, which needs 2 hits to pop him). But if he is in a contraption, try to destroy the contraption and then defeat Hekto Porko with the birds, we have the strategies to pop Hektor Porko in each level page that has him.

Mirror Worlds trailer
Before the gameplay, Hektor Porko laughs and then appears in the gameplay. He appears at the end on the right along with two King Pigs and two Alien Pigs?! Isn't that weird because there's usually only meant to be one of each at a time. Thanks Rovio, logic makes no sense now.