Ordinary pigs - just a bunch of green pigs. They sometimes wear different hats.
Soldier pigs - pigs who wear a pilot hat. they are hard to destroy. One of them is protecting the king pig.
Mr. Moustache - a pig who has a moustache. One of them is the king pig's butler.
King pig - he is the leader of all pigs. The final boss in all angry birds ( except angy birds rio ).