Horrid Shrieker

I only Battled It once but from what I could tell, the shrieker will flee the fight if it kills one of your characters, right after that you complete the Dungeon. It had something around 250 hp I believe. The shrieker also kites you with it's nest, as in the boss bounces from 1st to 3rd position (Because her nest takes up two character slots). The boss has a lot of dodge, so bring someone who can mark the shrieker.