I know someone who had a Siamese, and when someone broke into their house, the cat attacked the bugler . They woke up to this guy screaming, and saw him leave the house with the cat on top of his head. Cat came back a half hour later looking very proud of himself.
One of my cats used to go protect another of my cats anytime she used to get into a fight. Think his attitude was 'That's my cat to abuse, not yours'.
Edited by ramoss, : No reason given.