I found this awesome mod that lets you fight a bunch of monsters like the Mob Arena. It's called the Battle Tower. I watched a couple vids
on it and it was AWESOME!!!!! Basically you have to start on the 1st floor and fight your way to to the top of the tower. It gets harder and
harder as you move up the tower. At the end there's a big golem that gives you diamonds I think if you kill it. There's chests with loot in it
on each floor which youi can get after you take down the monsters. The bad part is that you have to bring your own weapons and armors
and food and stuff like that to the tower (unless you change that up somehow). One problem: There's a way you can cheat. I don't think I
should write it here in case Joe adds this mod to the server.