The Attachable Grinder mod is one of the best in terms of the time it can save you. Before getting to that though, it’s probably best to start off with a quick synopsis of this fantastic mod. The mod adds a single item to Minecraft – the attachable grinder. This can be placed on any of a number of different mobs and will last permanently once used, so you can’t get it back by killing the mob. Once attached, a grinder will begin to spit out items the mob would drop on death, without actually killing the mob. Basically, this is like a highly portable, far faster way to amass mob drops than building a spawner.
The Attachable Grinder mod isn’t perfect, but it’s about as close as a Minecraft mod can get to perfection. The only problem is that the grinder doesn’t work on every mob in the game. This will probably be resolved with a future update or two. Currently, the grinder will attach to six different mobs, even some hostile ones. It works on pigs, cows, chickens, zombies, skeletons and creepers. That last one is especially nice since you can use the grinder to farm gunpowder without ever putting yourself at risk of being blown to bits.
If you’re worried about your grinder targets despawning when you move too far away or log off of your world, don’t. Like the name tag or any dropped item a mob picks up, the grinder will prevent the target from fading out of existence, which means it will be there when you return, whenever that might be. The grinder itself won’t function while you’re far away or offline, so don’t expect to come back to your game after a long absence and find yourself drowning in bones or bits of rotten flesh. If you hate building spawners, the Attachable Grinder mod is absolutely for you.
It works on 6 mobs:
Download Links for Attachable Grinder Mod
for Minecraft 1.8
for Minecraft 1.7.10
Credit: iChun – Official Website