According to tibiopedia.pl you can find Mole amond Warzone 4 and Warzone 6 areas.
In my opinion there is no good place to find this creature, because on Warzone 4 you can find only 4 of them:
While on Warzone 6 the situation looks even worse:
As you can see, there's only 3 of them here.
So in my opinion completing Mole position in bestiary is only for those who want to have literally everyrhing in their bestiary. If you don't care about this challange and you care only about points to make your game easier - skip it!