diff --git a/src/main/kotlin/com/lop/devtools/monstera/addon/entity/behaviour/SysSpawnRule.kt b/src/main/kotlin/com/lop/devtools/monstera/addon/entity/behaviour/SysSpawnRule.kt
index 782866f..6964019 100644
--- a/src/main/kotlin/com/lop/devtools/monstera/addon/entity/behaviour/SysSpawnRule.kt
+++ b/src/main/kotlin/com/lop/devtools/monstera/addon/entity/behaviour/SysSpawnRule.kt
@@ -14,6 +14,26 @@ open class SysSpawnRule(private val entityId: String, private val entityName: St
         }
     }
 
+    /**
+     * ```
+     * weight()
+     * densityLimit()
+     * spawnsOnBlockFilter = mutableListOf("")
+     * spawnsOnBlockPreventedFilterData = mutableListOf("")
+     * spawnAboveBlockFilter { }
+     * herd { }
+     * permuteType { }
+     * brightnessFilter { }
+     * heightFilter {  }
+     * spawnsOnSurface()
+     * spawnsUnderground()
+     * spawnsUnderwater()
+     * disallowSpawnsInBubble()
+     * spawnsLava()
+     * biomeFilter { }
+     * difficultyFilter { }
+     * ```
+     */
     open fun condition(condition: BehSpawnRules.Condition.() -> Unit) {
         file.condition(condition)
     }
diff --git a/src/main/kotlin/com/lop/devtools/monstera/files/beh/spawnrules/conditions/BiomeTag.kt b/src/main/kotlin/com/lop/devtools/monstera/files/beh/spawnrules/conditions/BiomeTag.kt
index 77d19f9..58612dc 100644
--- a/src/main/kotlin/com/lop/devtools/monstera/files/beh/spawnrules/conditions/BiomeTag.kt
+++ b/src/main/kotlin/com/lop/devtools/monstera/files/beh/spawnrules/conditions/BiomeTag.kt
@@ -1,45 +1,80 @@
 package com.lop.devtools.monstera.files.beh.spawnrules.conditions
 
+import com.google.gson.annotations.SerializedName
+
 enum class BiomeTag {
+    @SerializedName("animal")
     ANIMAL,
+    @SerializedName("beach")
     BEACH,
+    @SerializedName("birch")
     BIRCH,
+    @SerializedName("cold")
     COLD,
+    @SerializedName("dark_oak")
     DARK_OAK,
+    @SerializedName("deep")
     DEEP,
+    @SerializedName("desert")
     DESERT,
+    @SerializedName("edge")
     EDGE,
+    @SerializedName("extreme_hills")
     EXTREME_HILLS,
+    @SerializedName("flower_forest")
     FLOWER_FOREST,
+    @SerializedName("forest")
     FOREST,
+    @SerializedName("frozen")
     FROZEN,
+    @SerializedName("hills")
     HILLS,
+    @SerializedName("ice")
     ICE,
+    @SerializedName("ice_plains")
     ICE_PLAINS,
+    @SerializedName("jungle")
     JUNGLE,
+    @SerializedName("lakes")
     LAKES,
+    @SerializedName("lukewarm")
     LUKEWARM,
+    @SerializedName("mega")
     MEGA,
+    @SerializedName("mesa")
     MESA,
+    @SerializedName("monster")
     MONSTER,
+    @SerializedName("mooshroom_island")
     MOOSHROOM_ISLAND,
+    @SerializedName("mountain")
     MOUNTAIN,
+    @SerializedName("mutated")
     MUTATED,
+    @SerializedName("nether")
     NETHER,
+    @SerializedName("ocean")
     OCEAN,
+    @SerializedName("plains")
     PLAINS,
+    @SerializedName("plateau")
     PLATEAU,
+    @SerializedName("river")
     RIVER,
+    @SerializedName("roofed")
     ROOFED,
+    @SerializedName("savanna")
     SAVANNA,
+    @SerializedName("shore")
     SHORE,
+    @SerializedName("stone")
     STONE,
+    @SerializedName("swamp")
     SWAMP,
+    @SerializedName("taiga")
     TAIGA,
+    @SerializedName("the_end")
     THE_END,
+    @SerializedName("warm")
     WARM;
-
-    override fun toString(): String {
-        return super.toString().lowercase()
-    }
 }
\ No newline at end of file
diff --git a/src/test/kotlin/com/lop/devtools/monstera/addon/entitiy/SpawnRuleTest.kt b/src/test/kotlin/com/lop/devtools/monstera/addon/entitiy/SpawnRuleTest.kt
new file mode 100644
index 0000000..d5f3e3d
--- /dev/null
+++ b/src/test/kotlin/com/lop/devtools/monstera/addon/entitiy/SpawnRuleTest.kt
@@ -0,0 +1,52 @@
+package com.lop.devtools.monstera.addon.entitiy
+
+import com.lop.devtools.monstera.addon.buildTestAddon
+import com.lop.devtools.monstera.addon.testAddon
+import com.lop.devtools.monstera.files.beh.spawnrules.PopulationControl
+import com.lop.devtools.monstera.files.beh.spawnrules.conditions.BiomeTag
+import kotlin.test.AfterTest
+import kotlin.test.Test
+
+class SpawnRuleTest {
+    @AfterTest
+    fun buildTask() {
+        buildTestAddon()
+    }
+
+    @Test
+    fun spawnRulesTest() = testAddon {
+        entity("spawn_rule_test") {
+            behaviour {
+                spawnRule {
+                    populationControl(PopulationControl.ANIMAL)
+                    condition {
+                        weight(2)
+                        biomeFilter {
+                            filterEntry(BiomeTag.OCEAN)
+                        }
+                    }
+                }
+            }
+        }
+        withJsonFile(config.paths.behSpawnRules.resolve("spawn_rule_test.json")) {
+            assert(
+                this.containsKeyChainValue(
+                    value = "ocean",
+                    "minecraft:spawn_rules",
+                    "conditions",
+                    "minecraft:biome_filter",
+                    "value"
+                )
+            )
+            assert(
+                this.containsKeyChainValue(
+                    value = 2,
+                    "minecraft:spawn_rules",
+                    "conditions",
+                    "minecraft:weight",
+                    "default"
+                )
+            )
+        }
+    }
+}
\ No newline at end of file