Does aggressive have a tender side?

In late December, I wrote the following draft:

For a dog who previously had huge aggression issues, Dennis is turning out to be quite a teddy bear!

He still has days when he is immensely uncooperative and prefers being the hunter rather than the herder, but then he has other days when he's just being himself and tries to make contacts with the animals now occupying his former kennel.

Then my dad came to visit, and the dog bit him (totally unprovoked)! So much for our tough guy having a tender side! But to end with a true Ishtar thought: "Hey, at least I'm glad I don't have small children!" But I haven't given up on him yet. Am in no position to either, since he's a fabulous guard - just has to work on his social skills...

Ishtar