My fierce little 9-pounder tabby "Dayhunter" has attacked both a(full-grown) husky and lab that came to visit. He sneaks up and then goes right for their faces, 9 lbs of spitting, furious outrage. BUT he gets chased across the yard by our red hens almost daily - I guess he knows they live here and he's not to hurt them.

I hope DH (yes, that's what we've called him for years) doesn't every meet up with a bear, though.