CobbleStacker

CobbleStacker is a server-side Fabric mod for Minecraft 1.21 designed to significantly reduce entity lag by intelligently stacking mobs, ground items, and spawners. Fully compatible with Cobblemon — all Pokemon are automatically excluded from stacking. Mob Stacking - Automatically merges nearby identical mobs into a single entity with a visible nametag (e.g. "x16 Zombie") - Respects mob attributes: variant, color, size, baby/adult, tamed owner, profession, and more - Configurable death behavior: KILL_ONE (kills one and respawns the stack with reduced count) or KILL_ALL (kills the entire stack with multiplied drops and XP) - Entities with name tags can be excluded from stacking - Blacklist support by entity type and world Item Stacking - Merges ground items of the same type beyond vanilla limits (up to 1024 per stack by default) - Custom nametags showing the real item count - Built-in auto-clear system that removes old item stacks after a configurable time, with a whitelist for valuable items - Manual clearlag command for instant cleanup Spawner Stacking - Stack multiple spawners of the same type by right-clicking with a spawner in hand - Floating hologram displays the spawner type and stack count - Mobs spawned from stacked spawners come out pre-stacked - Silk Touch support for spawner drops - Automatic spawner property repair to prevent broken spawners - Persistent data saved to JSON General - Fully configurable via cobblestacker.json - Admin commands: /cobblestacker reload, stats, info, kill, clear, clearlag, debug, fixspawner, setstack - Lightweight and optimized with batch processing, caching, and minimal overhead - No client-side installation required