My dog Kelly (she died a couple of years ago) hated people who spoke a different language.
My sister and brother in law took her for a walk and met this English tourist who really liked dogs and wanted to take pictures of her but she absolutely refused to come near him and just lurked in big circles around them, growling like crazy.

Same thing with a German tourist who accidentally bumped into our car and came to apologise. Lol, no damage was done and everyone was fine with it.. except the dog who acted like she wanted to kill him, so we were the ones who really had to make apologies.

-Varga