The birds attack a city of pigs. It's displayed in the end credits that none of the pigs perished.
After the hatchday party scene, Red is punching and smacking people on what they do.
During the scene where Blacksabath's song, Paranoid, is playing in the background, Red elbows a bird and bows up at another bird for being in his personal space. Also, he kicks a cute baby bird from the beach into the water for hitting his house with a ball. A bird is sneezing and gets snot all over Red and his popcorn so Red angrily slams the popcorn box over the birds head. A doctor bird is checking Red's reflexes and instead of his leg popping up, he slaps the doctor.
Red falls through a tree and hits 5 branches. On the last branch, he lands on his groin. And cries, "giblets".
A character gets in a fight with a bird-shaped wood sign.
A bird punches another bird across the room.
Bird paints a pig being electrocuted, hung over a fire with an apple in his mouth, shot out of a slingshot. Images are not grimly but comically depicted.
A pig says "we tried to kill them with kindness but now we'll just have to, well, you know."
Lots of explosions, the pigs fight with TNT.