Hi Arte!
How can I spawn animals, those are attackable? I found informations about combatant mode and I know, how to make trigger spawn when player is near. But mob is not spawned until player triggering spawn.

Its any way, how to make attackable mob, which is already spawned?

And second question, its possible to change props of spawned mob, especially his brain (AI)?

yes. there are examples of that in xmlextras.

Take a look at masterhelper.xml and changeling.xml