There's a quest in Arlathan to destroy the blighted deepstalker nest that's not not in the journal or on the map. However, it can be completed.
If you cleared this nest, then after the quest Blood of Arlathan, three adventurers will appear in the forest cooking a deepstalker near the campfire.
In the files, these guys are marked as an easter egg. Most likely, this is a reference to Dungeon Meshi.
They also have banter codenamed "dragonsnack" where they discuss the events in Arlathan Crater. Originally this was a conversation between the Veil Jumpers in their camp.
Guard: He wanted to strengthen his Archdemon by feeding it Dalish elves.
Guard: "Noble blood for a noble beast," or something like that.
Mercenary: That's vile.
Guard: Does it really make a difference, you think? Elven blood?
Mercenary: Does it matter if it does? Sacrificing people is still a horrible thing to do.
Guard: Anyway, he was telling them how disappointed he was in them for letting the Dalish escape.
Guard: And then he said: "This is merely a test of resolve. Mine, and yours."
Guard: Mostly theirs, I think, because then he asked the Venatori to give themselves to the dragon.
Mercenary: He asked and they just… did it?
Guard: Some seemed eager. Not all of them, though. I thought I caught blood magic in the air.
Mercenary: How did you get close enough to hear all of that?
Guard: Oh, I was… uh, I had to relieve myself in the bushes and when I was done there were Venatori everywhere.
Guard: So I just stayed in the bushes. The whole time.
Mercenary: You're lucky you weren't caught.
Guard: Almost was. Sneezed once. Venatori mages were using some magical powders, and the wind blew it over to me.
Guard: Thank the creators the dragon was louder.