This mod is made specifically for a modpack I am working on and will not be ported to other versions/modloaders, I recommend finding alternatives.

HOW TO USE:

Edit config/mobcontrol-common.toml in your instance folder (same place as other mods’ configs). Forge may create a .bak next to it when it saves; that’s a backup of the old file. Restart the game (or reload configs if your setup supports it) after big edits.

Two layers

spawnMode - broad rules for all mobs that go through Forge’s spawn checks (things that extend Mob in the usual spawn pipeline).
Per-entity lists - extra rules that apply even when spawnMode is off.

spawnMode values (must match exactly, including capitals)

OFF - No global spawnMode blocking. Per-entity settings below still apply.
NATURAL_ALL_DIMENSIONS - Blocks natural-style spawns everywhere: natural tick spawns, chunk-generation spawns, patrols, reinforcements, structure-based spawns. Does not target /summon, spawn eggs, spawners, or breeding by itself (those are separate spawn types).
NATURAL_LISTED_DIMENSIONS_ONLY - Same natural-style block as above, but only in dimensions listed in naturalSpawnBlockedDimensions (e.g. minecraft:the_nether, minecraft:the_end).
ALL_MOB_SOURCES_EXCEPT_CHUNK_LOAD - Aggressive: blocks Mob creation from most sources (including commands, eggs, spawners, breeding, natural, etc.). Saved entities still load with the world; the mod avoids breaking chunk load the same way older “LOAD” hacks did.

Per-entity lists (work with spawnMode = "OFF")

naturalSpawnBlockedEntityTypes - List of entity IDs ("minecraft:zombie", "iceandfire:hippogryph", …). Those types cannot use natural-style spawns in any dimension. /summon, spawn eggs, spawners, and breeding are not blocked by this list (unless you also use ALL_MOB_SOURCES_EXCEPT_CHUNK_LOAD).
naturalSpawnBlockedEntityDimensionPairs - Entries look like "entity_id|dimension_id" (both full IDs, one pipe). Same natural-only behavior, but only in that dimension. Example: block natural endermen only in Nether and End:
"minecraft:enderman|minecraft:the_nether", "minecraft:enderman|minecraft:the_end".

naturalSpawnBlockedDimensions
Only used when spawnMode is NATURAL_LISTED_DIMENSIONS_ONLY: list of dimension IDs where all natural-style mob spawns (for normal pipeline mobs) are blocked, not just specific entity types.

Tips
Use /forge entity list or your mod’s registry / F3 + tooltips to get exact entity IDs. If something still spawns naturally, it may use a path that doesn’t fire Forge’s mob spawn events (some mods do); in that case you’d need pack-specific tweaks or a different mod.

Configurable Mob Management