This mod is designed to allow map makers and mod pack builders to control which "dimensions" mobs are allowed to spawn in. This only prevents mobs that can otherwise spawn in a dimension to not spawn. It cannot make mobs that are not allowed to spawn, spawn.
Configuration File
To configure your whitelist/blacklist, edit the file config/MobSpawnTweaks.cfg and add a section like the following
dimension.0 {
S:whitelist <
Zombie
Skel.*
>
}
dimension.-1 {
S:blacklist <
net.minecraft.entity.monster.EntityPigZombie
net.minecraft.entity.monster.EntityBlaze
>
}
Modpacks
Feel free, a link back to here would be appreciated
Thanks!
Thanks to Thutmose, diesieben07, Orion, Mogul and everyone else on #minecraftforge that help each other out!

