King Slime

The King Slime is a mini-boss added in the 1.0.4 patch. As the King Slime takes damage, it slowly spawns additional slimes and also becomes smaller until defeated. The King Slime is considered a subspecies of Slimes in general because it uses the same AI and similar graphics.

Spawning
Inspection of source code has led to the following conclusions about King Slime spawning behavior.
 * The King Slime spawns only in areas a third of the map away from the spawn point. An easy way to determine if you are far enough from the spawn point is to check for the presence of bunnies, who only spawn within a third of the map from the spawn point. If you can see bunnies, you aren't far enough from the spawn.
 * The King Slime has a 1:300 chance to spawn, meaning a Water Candle can actually speed up the process of encountering the King Slime dramatically.

Strategy
The King Slime behaves exactly like a normal slime (it uses the Slime AI), except that it spawns other slimes after being hurt by the player. Due to its predictable nature, it is easy for a new player to defeat the mini-boss with even lower tier weapons. The only thing a new player should worry about is dodging the King Slime as it jumps about, as this could become a nasty fight very quickly. To finish the mini-boss quickly, projectiles such as Shurikens or Arrow (Which you use with Bows) are recommended. He can note as normal Boss.

Digging a pit two blocks wide is an excellent tactic for fighting the King Slime, which is too large to fit in such a small pit. Placing wooden platforms on top of the pit has the added benefit of keeping the smaller slimes out.

Drops

 * 1 Piece of Ninja Gear: 99.99% (9999:10000 chance)
 * Ninja Hood: 33.33% (1:3 chance)
 * Ninja Shirt: 33.33% (1:3 chance)
 * Ninja Pants: 33.33% (1:3 chance)

Trivia

 * If you look closely enough, you can see that there is a ninja inside the King Slime. This would explain why you get ninja clothes when you defeat it.