Making Bulls aggressive

Male animals (at least bulls and rams) will always attack you, but only if you attack them first (otherwise they're passive). Same about goats (both male and female). This feature is always active

Quote from angriff

hmm.. ok well i hit a bull with a hammer on my server and it just ran away so I thought it was a setting.

are you sure it was actually a bull? cows run away, so maybe you were mistaken.

if your in creative mode they ignore you even if u hit them.

Quote from angriff

Did not know the actual pronouns to use when hitting it but it was black and had horns. I did not remember seeing an udder though I was not sexing the cattle at that time.

the cows also have horns but i don't think there's a solid black cow model actually, so that does shed some light on the situation. odd.

If you come across a cow in the game and want to know whether it really is a cow or a bull, carefully pull up its skirt and you'll see the difference

The black cow was indeed a bull btw (there is no black cow in the game, just a black bull)