minecraft-source/src/net/minecraft/world/entity/MobSpawnType.java

package net.minecraft.world.entity;

public enum MobSpawnType {
    NATURAL, 
    CHUNK_GENERATION, 
    SPAWNER, 
    STRUCTURE, 
    BREEDING, 
    MOB_SUMMONED, 
    JOCKEY, 
    EVENT, 
    CONVERSION, 
    REINFORCEMENT, 
    TRIGGERED, 
    BUCKET, 
    SPAWN_EGG, 
    COMMAND, 
    DISPENSER, 
    PATROL;
}