Cursed

  For this boss you will want a sizable arena and some campfires.

 You will have to wait until it's dark out, once it is, I recommend doing it when it first turns night but talk to the NPC walking around near the dungeon. The dungeon is always located on the opposite side of the map, from where ever the jungle is.

 This is the hardest pre hard mode boss fight in the game as you have to watch out for his hands too. Though you don't have to kill his hands to defeat this boss you can if it makes the fight easier