Knights should approach them fast before they shoot more Arrows. A good strategy for knights would be to run towards them in full defence and once you are near them, attack with full attack. Because of the hunter low defence a knight can kill him easily.
Paladins should not fight these creatures unless they have the Invisibility Spell, shield or skill enought to kill them in 1 shot, and if your planning to kill it without spell or runes put yourself in Magic Shield and must have a distance of around 50 to kill it fast.
Mages should use Invisible or if they are hunting them they should summon monks. Overall, stay away from these unless you have to get through them to get to where you want to hunt (e.g. Heroes) or if you need to get a pair of Sniper Gloves. They usually aren't worth the trouble.