Prisoner Pigs

Prisoner Pigs are two pigs that only appear in the Angry Birds Toons episode Hamshank Redemption. They never appear in any Angry Birds game, and probably never will. The main difference between the prisoners and normal Minion Pig are the bushy eyebrows.

Normal Prisoner Pig
This pig was imprisoned for breaking the rules of Pig City. Throughout the episode, he tries to run away. Distinguishing features: small specks on the side, big bushy eyebrows across which are small scars, and a bulging lower jaw with one tooth sticking out of his mouth.

Goliath Pig
A stronger prisoner pig. He is very mean, and resembles the Fat Pig a little. He is a different color from the other pigs, just like Corporal Pig in Angry Birds Toons. He is strong but not very smart. He also has a tattoo on his chest.

Trivia

 * It is possible that the normal Prisoner Pig appeared in the episode Hambo.
 * The prisoner pigs are the only pigs that didn't appear in regular Angry Birds games.