Each episode is named after each of the Harry Potter books and movies.
Red bird: Harry Potter (He is a bird despte having the surname Trotter.)
Big Brother Bird: Hagrid
Yellow bird: Ron Speedsly
Blue bird: Hermione Granger
White bird: Albus Dumbaldore
Black bird: serious Black bird
Green bird: Professor Mcgreenagle
Orange bird: Nevel Longbottom
Ice Bird: Proffesser Lupin
Mighty eagle: the mighty Patronus
Buck Beak (Has the power to Vibrate like Blu from angry birds rio)
Phoenix (Has the power to burn wood, but only wood, and all other materials on the structure will get minimal damage when hit.)
Occasionally other birds such as Luna Lovegood (yellow bird) and Arthur Weasly (black bird) and others may appear in several levels.
Pigs (in order of stength):
King pig: Lord voldamort dont mention his name
Mustache Pigs: Death Eaters
Helmet pigs: werepigs
Average pigs: slytherin pupils
Dementer pig: it floats about randomly
All the levels are based on harry potter based things such as classrooms in Greenpigwarts, rooms in the ministry of magic and the Burrow and creatures such as the dragons.