Welcome to my ap mumu build in this build you will get a item build,rune reason and awesomeness of other things.

For items I get these because they provide very early game sustain,speed and damage.The zhonay's can be replaced with the septer depending on enemy teams.The rabadons provide INSANE ap and is almost required in any ap build.RoA gives nice ap and health,which isn't bad at all.The boots can be sorc or cd boots,deepends again on the ememy team.The rylies gives slow,which is very nice and hp which again,IS NOT BAD.Void staff can be replaced with WotA if again THE ENEMY TEAM is doing.

For runes I take mpen,armor seals,ap per lvl glyphs and flat ap.In my opinion you can get ap for marks or mana seals,these provide nice things for Amumu too.

I use 21/0/9 masteries because this prvoies nice mana regen and some ap.Other good choices would be 21/9/0 or 9/21/0

I use flash because you can reach people without them even THINKING.Ignite is to improve burst,but you can get tleport or anything really.

Sorry for no pictures >.< this is my first mobafire guide