the same monsters but different exp and dmg ?!!

some of the lizard snipers on the field of silence do 5xx dmg per hit while most of the others (same kind) are doing 13x dmg ?!!

also, some of them only give 16xx exp and the rest is giving 20xx exp...

I am one shotting all of them though..

can anyone explain that please ?

There are two types of them, there are also two types of the shaman as well. One of the lizardman types has resistance to daggers and etc the other doesn't. The one with the resist's gives more xp. Also one of the shaman has magic resistance, he gives more xp than the other type of shaman.

look at the buffs the Lizardmen have.
Shamans, Snipers and the Ogres have two different kinds with different buffs, and so strenght, experience and different behavior in socialising each others.
Learn it, it also will help you to survive more often ;)

always hunt the mobs with more resistances/skills/abilitys, they give a lot more xp for each of them :)