Rat King

"This creature is the most unsettling of all the natural denizens of Sanctuary. The male of the species carries the eggs which the female deposits on his back. In their larval state, they burrow into the male's back, creating visible protrusions. They eat their way out of these protrusions when the host is attacked."

- Abd al-Hazir

Rat Kings are a type of Beast enemies, added in patch 2.3.0 in Diablo III. They can only be encountered in in Ruins of Sescheron.

In-game
Rat Kings are usually found dormant. When disturbed, they spawn a horde of Plagued Vermin and enter battle. In combat, they deliver very fast melee blows, and move surprisingly quickly for their size.

The rats they spawn may be regular or explosive, the latter being able to detonate for average Poison damage in few yards.

A new portion of rats may spawn every 10-15 seconds, up to a dozen at a time. There is no limit of how many can be spawned at a time, but rats are very weak and fragile.

Upon death, a whole nest of rats erupts from Rat King's corpse to attack the player.

Variants

 * Hive Mother (Greyhollow Island)

Uniques

 * Hamelin (Rift Guardian)
 * Necrotic Vector (Pestilence Master's Shroud Set Dungeon)

Development
Prior to release of Ruins of Sescheron, Hamelin the Rat King was the only known Rat King in game. Prior to the patch's release, Hamelin was planned as a "twisted natural creature" found in the Dreadlands in.

Rat Kings originally had antlers and even other joking horn forms (see artwork).

Later this model was used for the Hive Mothers.

Trivia

 * Upon death, the Rat King's carcass will remain, several rats lurking in it, going in and out, and looking around.