Kruz the Doberman is very suspicious of unfamiliar things. He knows he needs to keep his family safe, and doesn’t like things hurting other things!
His owner recorded this particular instance when Kruz got mad at the spider on the front door for catching an innocent fly with it’s web! How dare that spider hurt the poor, innocent fly? Kruz might look menacing, with his dark fur and those pointy ears, but deep down, he is just a big old softy!
Dobermans were originally bred to be protection dogs; they look menacing and intimidating, always willing to protect their owners, but obedient enough to do it strictly on command! For what it is worth, that fly was happy to have Krus on her side, even if it were for such a short time!