CustomMobSpawner Single Player Only? - Java Edition Support

I would like help with my custom mob spawner only spawning one mob : r/Minecraft

can i haz help? (need mod help) - Mods Discussion - Minecraft Mods - Mapping and Modding: Java Edition - Minecraft Forum - Minecraft Forum

Nightmarefuel Craft 1.12.2 Minecraft Mod

Does somebody know from which mod is it ? - Mods Discussion - Minecraft Mods - Mapping and Modding: Java Edition - Minecraft Forum - Minecraft Forum

The 10 Best Minecraft Mods Anyone Can Use

Custom Mobs for Java Minecraft - VANILLA! NO OPTIFINE NEEDED

FactionsShop, [1.14], [Drag-N-Drop!] \

1.7.10]GT-New-Horizons[Ultra Hard Gregified modpack via Minetweaker and Modtweaker][2,5K+ Quests], Page 45

Zyin's HUD - Minecraft Mods - Mapping and Modding: Java Edition - Minecraft Forum - Minecraft Forum

Mods other than Forge wont load - Mods - Forge Forums

6 Awesome Facts You Need to Know About Minecraft Mob Spawner