Yeah, chickens can be ruthless sometimes. I use to have two roosters, they were brothers. When they got older, one killed the other one. I have a scar on one of my legs from a rooster, he latched right on me with his talons. When it came time for the freezer, he wouldn't put his head on the chopping block. I ended up shooting him in the head with a .22, and then chopped it off. Even without his head, his body probably flew a good 20 feet afterwards. That was one mean rooster.
I've seen the hens go after frogs that have mistakenly entered the chicken yard. I wouldn't want to fall down in a chicken yard, they would definitely peck.
But Goose-zilla is more aggressive than the chickens, even our Great Pyrenees avoids Goose-zilla.