I never tried to pet him, I think that is just for dogs and cats. But I think that it's awesome that he is that mean! I don't know why, but I have always love mean animals.
All I ever did was feed him, and I did not do it all that much. But one of the funniest things he ever did was when he was in the 85 hex tank. He would see his reflection in the lid or something, and just stare himself down, but once in a while I would hear a good thump and the water would be all crazy at the top because he just attacked his reflection. For a fish that size it was a pretty hard hit on the glass, I always found it funny.