
Originally Posted by
Wizerd
Each monster will only ever spawn as a certain job, in terms of the DAT files. However, there are cases where it'll choose between certain monsters to spawn on the same timer. For example, in the DATs, there might be a Goblin Pathfinder followed by a Goblin Smithy (I dunno which line up with which, Goblin-wise). But when the mob chooses to spawn the monster, it'll spawn as one or the other, and the one that wasn't spawned can only spawn if the previous one was killed.
Beastmen strongholds are a prime example of this behavior, but there are other cases. (Kuftal Tunnel, Amemet's placeholder can be one of two lizards in the DAT files, but will only one will ever be up at a given time.)