Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Ok, this is my Third build, on my personal favourite champion.
This focuses on Tanking like the wall that Amumu is.
Leviathan is a wonderful item with Amumu, as you SHOULD NEVER die, even though you'll be taking the hits for the team.
Any Comments on the build please post.
A guide will follow if people like the build.