The animals no longer despawn and their spawn is based on the biome seed. In other words, the randomness of spawning was removed. There are several mods that relied on the prior mob spawning method to add custom mobs to the game, like Mo’Creatures, More Creeps and Weirdos, Humans+ and many more.

How to install:

  • Download and install Minecraft Forge.
  • Download the mod.
  • Go to %appdata%.
  • Go to .minecraft/mods folder.
  • If the “mods” folder does not exist you can create one.
  • Drag and drop the downloaded jar (zip) file into it.
  • Enjoy the mod.

Custom Mob Spawner Mod Download Links:

Older versions:

For 1.5.2

For 1.6.2

For 1.6.4

For 1.7.2

For 1.7.10

For 1.8

Credits: DrZhark