Did you notice any unusual terrain nearby? That early it would have had to have spawned from what would probably be a Dead Side Gate on, like, turn 1. If it was there literally from the getgo, like on your first turn, unless there was an Event that brought it in (Undead Uprising, maybe?) I can't think of any way it would be there.
Viewing post in Caverns of Xaskazien II comments
No idea how it got there, and I don't know if it was there turn 1 or not. I moved a few steps West, looked around for a few turns, then headed back East towards my starting square, and as I approached I saw her. May have been turn 15? 20? Don't remember if there was any unusual terrain...was too focused on her lol - I should have looked around and tried to notice. No event popped up or anything. Next time I see a 20+ OOD I'll try to gather a bit more info. Thanks! :