OK, currently there are aggressive enemies that run towards you and attack you (like a wolf or bear or lion or tiger), cowardly enemies that run away from you unless you click on them in which case they run towards you (like a rat or deer or elephant or gnome), and enemies that totally ignore you unless you target them, in which case they either run towards you (like a horse) or away from you (like a pigeon). This is all a nice and good variety but I think we can add a new type:
Enemies that freeze and don't move if you select them for an attack. This would work especially well with deer (deer in headlights are known to freeze in place). Basically, enemies have a fight-or-flight response currently, either going towards you to attack and fight, or running away from you, fleeing. But this doesn't cover the full array of stress responses by wild animals; certain animals freeze in place and stop moving, when they are stressed out. This behavior is not just observed in deer, but many other life forms; I have personally seen it happen with lizards (both in anoles and salamanders). As a real-life example of this, once I caught an anole lizard with my bare hands, and it was terrified, but I didn't damage it in any way, just showed it to my parents, then I set it down outside in the middle of the grass. But instead of crawling or running away it just stayed still. An hour later I went back and it was still frozen there (but obviously still alive and well, because it was breathing and everything). Then a few hours after that I checked again and the lizard had calmed down enough to leave the spot where I set it down in the grass, wasn't there anymore, meaning it obviously must have come to its senses and finally moved again and gone back to normal. And sometimes people freeze as a stress response (typically in humans this is called a panic attack, something I am familiar with firsthand). But it is a really major stereotype with deer, about them freezing in place when they are scared; this happens all the time with deer in car/truck headlights, although typically in the real world, deer run away from human beings and only freeze in front of motor vehicles. Still, it would be fun/funny to add deer freezing in place to the game, even if the game does not have motor vehicles which are what typically causes such behavior in real-life deer.
Anyway, certain enemies (I would start out with just deer) ought to stay in place and not move if they are targeted for attack (have a red circle around them), by any attacker who is a high enough level above them to frighten them so much that they freeze in place. But a lower-level attacker would not frighten a deer to such an extreme degree to make it freeze in place, so it would just run away like it currently does.
So to summarize the proposed feature, if you are high level (for now let's say level 20 or above) and target a deer, it should freeze in place and be too afraid to run away (but it WILL fight back if you are next to it). And if you are low level, the deer won't be THAT frightened of you, and will just run away normally. And perhaps this can also be applied to a few other cowardly enemies (maybe rats), but not all of them (definitely not gnomes or elephants), it is good to have variety in the behavior of enemies. I would only have this behavior in the most low-level of cowardly enemies that give the least amount of experience, definitely not have anything that gives more than 10 experience freeze in place. So, I propose just doing it on cowardly enemies such as deer and rats that give less than 10 experience, and not on cowardly enemies such as gnomes or elephants that give 10 or more experience. And these very low experience enemies should only freeze in place if targeted by characters that are, oh, say, level 20 or above.
Anyway the point of this is to increase the variety of behaviors of enemies in a way that makes logical sense and also creates different gameplay experiences for low-level and high-level characters when fighting the same enemies (i.e., the enemies behave differently). I also have a few other ideas on changing enemy behaviors but I'll just suggest this one for now; my other ideas aren't as fully thought-out yet and aren't ready for me to propose yet.