Examples from our shelters: Honey and Betsy were both very sweet and docile when they first arrived, but with the birth of Betsy's son Nutmeg, both girls became a little sassy, running caregivers out of the pasture in the evening when they would call the cattle in for the night.
And I'll never forget our 2004 rescue of a herd of 26 starving, pregnant cows. The friendliest mother actually turned on me shortly after her calf was born and we attempted to snap a photo. I was left with a black eye and crushed equipment!
Chickens make amazing mothers and although we do not allow breeding at our sanctuaries we have had mothers arrive with babies. Mother hens are so protective of their children that you often cannot see the chicks when you first arrive in the barn. Moms puff up and hide their babies beneath them to ensure that not one single chick is taken from their brood. Even as their children grow, mothers shield them under their wings at night safeguarding them from harm. Chicks cannot get wet and mothers cover them in the rain.
Mother chickens have such incredible maternal instincts that they will even look out for or even take on the children of other mothers when duty calls. We have seen this in cases where multiple mothers come in with chicks of varying ages and sizes that are clearly not all from the same clutch. They often take them on and nurture them like they would their own children.