This is for those people who like to battle a large verity of mobs. The boss is a mega spider. How, you say? Well, 8 stacks of cows with a blaze on top leaded to a zombie/skeleton. If zombie, you have to defeat the legs (cows) and defeat the zombie on it's own. If skeleton, you just have to defeat the skeleton by the way above, or just defeating the skeleton, with all 8 legs. It will drop this- 8-22-String (100%) 4-11-Shiny Item From Enraged Spiders (100%) 8-22-Shiny Item From Enraged Spiders (75%) 1-Woven Blade (Stone sword) (5%) 1-Woven Armor Set (White Dyed Leather Armor) (2%) Leave a +1 or a +1,000,000 due to your mobs!
Aikar already has 2 more mini-bosses coming in I believe, and Reysik the dragon will be added in Dragon Tombs. No more mini bosses needed for now.
Flee from the back. Plus, it would be harmless until you destroy the legs if the boss part where a zombie. Edit-ninja'd Reysik the dragon is the dragon tombs boss.