Add the rat king.

assets/config.json

@@ -11,6 +11,7 @@
     "armored_knight": "assets/armored_knight_1-256.png",
     "sword": "assets/cinqueda_1-512.png",
     "rat_with_sword": "assets/rat_with_sword-256.png",
+    "rat_king": "assets/rat_king-256.png",
     "barrel_small": "assets/wood_barrel_small-256.png",
     "hanging_brazier": "assets/hanging_brazier-256.png",
     "torch_pillar": "assets/torch_pillar-256.png",

assets/enemies.json

@@ -69,6 +69,20 @@
       {"_type": "Sound", "attack": "sword_1", "death": "monster_16"}
     ]
   },
+  "RAT_KING": {
+    "components": [
+      {"_type": "Tile", "display": "\u08ac",
+        "foreground": [205, 164, 100],
+        "background": [30, 20, 75]
+      },
+      {"_type": "Combat", "hp": 50, "max_hp": 50, "damage": 50, "dead": false},
+      {"_type": "Motion", "dx": 0, "dy": 0, "random": false},
+      {"_type": "EnemyConfig", "hearing_distance": 3},
+      {"_type": "Animation", "scale": 0.1, "simple": true, "frames": 10, "speed": 1.0},
+      {"_type": "Sprite", "name": "rat_king"},
+      {"_type": "Sound", "attack": "sword_1", "death": "monster_16"}
+    ]
+  },
   "SPIDER_GIANT_HAIRY": {
     "components": [
       {"_type": "Tile", "display": "\u08ea",