Minecraft - Tutorial: Hostile Mob System (Revised)

This tutorial teaches you how to build a simple and convenient (30x30) hostile mob system from scratch. I also attempt to explain some of the basics of mob spawning and how to improve the efficiency of your mob system with the least amount of effort. (Important Link) 4-Way Mobavator Tutorial: The OLD hostile mob system tutorial. Part 1: Part 2: Part 3: Part 4: