This kinda reminds me of when my mom stepped in between me and my dad in the middle of him beating me, and threatened to kill him if he ever hurt me again, even though he was twice her size.

2 years later, I saw my little poodle/terrier standing her ground against two Golden retrievers walking by, trying to protect her pups. The golden retrievers meant no harm, and were just trying to be playful, but my dog would have none of it and started snarling at the two dogs.

TL;DR: Moms of all species are awesome :)