How do you get a command block to spawn mobs? I have tried many things and none have worked. I want to know because I want to make a mob arena with not plugins or spawners.
Technically, command blocks cannot spawn mobs. The only way they could trigger a mob spawning device is with Wireless Command Block Redstone.. which would activate dispensers, perhaps with infinite mob egg stacks (using MCEdit or similar), and then the dispensers would be able to dispense mob eggs, in turn making mobs.
Check out the server I play on, timgaming.com. (website and ip)