What about a skill that players are able to tame animals? I mean only certain animals can be tammed(beasts, animals, dragons) and players can tame higher levels animals with higher level taming skill. The Tammed animals can attack, other players and can be sold/traded/gave to other players with lower taming lvl, but they will be tammed for shorter time and when they are no longer tamed, they attack the actual owner. The owner can use the animals to atack npcs or other animals, if your tammed animal dies in combat, they drop no loot and you will not be able to tame this kind of animal again for a long period of time.
