Karka Queen
- Hold all four settlements (Point Pride, Kiel’s Outpost, Steampipe Steading, and Camp Karka) to get her to spawn left of Steampipe Steading. She has a cooldown so won’t always spawn when all four settlements are controlled.
- You have 10 minutes to kill her. If you fail to do so she will respawn with full health at one of the four settlements.
- Defeating her give you a daily bonus chest with two rares and a chest on the ground that give you some karka shells and 2 random items.
- Defeating her should give you the Crazed Karka Queen achievement but this is sometime bugged.
Merchant
- This merchant is called Southsun Economist and normally sells white stuff unless all four settlements are held. You can find him in Steampipe Steading, Pearl islet and probably some other settlements as well.
- Weapons have basic starter skin and costs 2 gold and 70 karka shells for exotic, 20 silver and 5 karka shells for rare. They have random major sigils.
Armor have old skins (Conjurer skins for light, Banded for heavy, and Rogue/Pirate for medium) for exotic/rares and sells for the same price as the weapons
- Weapons and armor cannot be put in mystic forge or salvaged.
- Also sell two potions for 5 karka shells and 1 passion flower. One is Karka slaying and the other give +150 toughness
Contractually Obligated
- Talk to Inspector Ellen Kiel in Pearl Islet and she will have an option to enter a story instance.
- Make sure you don’t exit the instance until you get the achievement – you will need a bit after finishing the final cutscene.
Longer writeup with some maps/pics of armor etc
http://dulfy.net/2013/06/04/gw2-crazed-karka-queen-event-guide/