Spawns Most NPC's do not respawn once they are killed. There are a few exceptions on each map though. This is so you can "farm" gold and XP if you need/want to. Certain NPC's are always located at special locations. For example, the Dark rogue usually guards the scar area.
Attacking NPC's
The easiest way to take down NPC's is to use a ranged weapon from a far distance until they get too close. Once they are close, use a jump attack and then finish them off with regular attacks. Or if you can attack from a position that is hard to reach (eg. a tower), then the NPC's will get stuck and you can easily take them out with a ranged weapon.
Note that you can't block NPC attacks or special abilities! That's why you have to keep attacking and don't block. Another thing you can do is to attack them with a ranged weapon and then run into a bulletproof bush. For some reason they can't attack you there. See the video at bottom of the page.
Chiprel
Chiprels are tiny creatures that throw rocks at you in a very fast sequence. While they are easy to kill, do not under-estimate the damage they deal. It happens quite often that if you get too close to them that they start attacking you without noticing it. So keep an eye out for those little beasts...getting killed by a chiprel is very embarassing :)
Demon Boar
Demon boars can be killed quickly and but have a very annoying attack ability that slows your movement and attack rate (as far as I can tell). You should be able to take out a group of them by yourself right at the beginning of the match.
Monkit
Monkits have about the same health as demon boars. They can attack you both in close-combat as well as throwing their spears at you if you try to run away. You should be able to take out a group of them by yourself right at the beginning of the match.
Cickle
Cickles are really really nasty NPC's. Probably the most annoying in the game. They only have a ranged attack which deals some good damage to you. And they have an extra freeze ability which holds you in place while they keep shooting at you. You definitely don't want to mess with them all by yourself; they are tough to beat in groups or in combination with other NPC's.
Grandar
The grandar is sort of the small brother of the golden troll. He is a pure melee NPC and has a short stun ability. His stun ability cannot be blocked, which makes him very annoying. He usually uses his stun ability after the second or third attack.
Golden Troll
The golden troll probably has the mostHP of all NPC's. His abilities and attack pattern is the same as the grandar. You should not attack this NPC alone by yourself if you're on a low level.Very important to know: This NPC will give you a soul if you kill him.
Dark Rogue
These NPC's are usually protecting the area around a scar around the map. They have relatively low HP but they deal a lot of damage if you can't take them out quickly. The dark rogue will give you a soul if you kill him.