Hello guys! I've been derping with this green mummy for some time now, and i think i found a really nice build. I'm not saying it's the best, but it's been working great for me so i decided to share. I will be happy to clarify in case you get confused about anything in my build; and i will also be grateful if you post alternative playstyles - i like playing amumu and more ideas on his gameplay are always nice :)

Since i play amumu with maxed despair, i want to catch my enemies. I use Greater Quintessence of Movement Speed to further boost this stat. Earlier on, i used Greater Quintessence of Armor for better and safer jungling - the 12 extra armor really helps a lot. So if you ever have problems killing the jungle creeps, try switching to those.

For seals, i get Greater Seal of Armor for armor. This allows me to start with a Regrowth Pendant instead of a Cloth Armor, since my starting armor is sufficient.

For glyphs, i take Greater Glyph of Magic Resist, since many casters have spell penetration and having some magic resistance reduces their damage considerably. You could also try getting Greater Glyph of Scaling Mana Regeneration for better mana sustain. It will allow you to run around a bit longer without blue.

For marks, i take Greater Mark of Attack Damage. Why? Cause i have them. Get creative here and take whatever you want to.
Why don't i take spell penetration marks? Cause i am building a tank, and i will deal the damage overtime anyway. Having a faster early jungle is more important to me.
Also, both attack speed and armor pen runes give less damage in jungle than attack damage ones.
If someone could do the math for me and prove that spellpen runes give better early jungle than ad ones, i will gladly switch (but i am lazy to do the math right now).

I get defensive masteries with spell penetration with amumu. Pretty straightforward. If you have your favourite masteries that differ from mine, change this. The important idea here is that i take defense with spellpen.

Amumu can kill jungle easy. All he needs for that is a bit of health and mana regen - all of which are provided by a philosopher's stone.

Next, you are here to help your allies, not run around the jungle like a berserk and kill anything you find there. You will need Boots of Swiftness to do that well.

After that, there is a time when you don't really need anything. Buy some wards and ward top, buy a pink and kill the enemy bot ward (if it's up). Get a few pots.. and farm your jungle, gank the lanes, do stuff. This is the time when you are the strongest and you should use it.

After you get back, buy yourself a kage's lucky pick and a Heart of Gold to further boost your advantage. After that, feel free to run around and have some fun. With those 4 items, you got all you need for quite some time.

After you start getting hit a bit too hard, get either a Thornmail, or some other armor item. I wouldn't reccoment rushing Frozen Heart, since it's kinda expensive. Look at the enemz team and if you see people having big attack damage, get the thorns. On the other hand if you see vayne or kogmaw, get something else instad (maybe Glacial Shroud).

After this, you need HP and magic resist. Ideal item is Spirit Visage, since it gives you both and some cooldown reduction as a bonus. And it's dirt cheap. But you can always get Force of Nature instead, or even Banshee's Veil, if you need mres and hp.

In case you go for spirit visage, replace it with banshee as your last item choise.

Lastly, Aegis of the Legion is a very nice item, which allows you to help your team, and get some more hp and magic resistance. Alternatively, you can go for Lich Bane, if you feel you need more damage.

Max Despair.
A) It costs the least mana for the most damage
B) It allows you to deal damage by just running around your enemies

Second, max Bandage Toss.
A) It really hurts when you gank

You can also max Tantrum second for better jungle sustain - the damage for ganks should be similar. Suit yourself. Just be careful not to use it too much in the jungle or you will be mana starved and will require blue buffs all the time, not being able to give them to your midder.

Why Exhaust? It's simple - better ganks. And in late, you can always disable an enemy ad champion and make yourself even more useful.

I tryed Heal, but it was really useless. In theory, i should heal my allies while ganking, but in practice i was always too far away from them.

Tryed Ignite, but people kept being just out of it's range, or running away ignited. Exhaust seemed better, since i need to cry near them.

Also tryed Ghost. Was briliant, noone gets away. But i eventually switched to exhaust, since it enables my allies to catch up to the enemy as well. Ghost also enables you to survive better when ganked in your forest. Anyway, ghost is good, so is exhaust. Suit yourself.

Flash. The uber-needed-cannot-miss spell for amumu. Wrong, you have a bandage toss, use it and get a ghost or exhaust. Get flash only if you play ap amumu.

This amumu playstyle revolves around you being fast. This means you will tag your enemy with a bandage toss and never let go. He cannot run, he cannot hide, you are always there, crying and making him sad. For this you take the Boots of Swiftness, Force of Nature and Greater Quintessence of Movement Speed.

In order for this to work, you need to survive the enemy if he decides to kill you off instead of futile running. Early on, you have your runes for this.
Later in the game, you will start getting resistances against the biggest enemy damage dealer. Thornmail, Spirit Visage / Force of Nature

Why take the gold per 5 items? Because you can afford it! You can use all 3 of those items, and for every moment you have them, you get extra gold. Remember me saying, that after getting a philo and boots, you really don't need anything else? Well, if you don't need anything, you might as well get the gp5 items and think about more gold later when you will need it.

Bandage toss @ ganks
When you gank, dont use your bandage toss right away if your enemy sees you. Walk to cut his path, wait for him to waste his flash before bandaging. Never just walk into the lane and from max bandage range do "hek!" and miss the frikin bandage - that is bad. Wait, take your time. If you cut the enemy path, he can only run throught you or though your ally so chill and aim well.

Ultimate @ ganks
When you gank, use your ultimate if it leads to a kill. It is good, it is what you want. Ideal thing to do is bandage toss, if he runs / flashes, ult. If he still evades, exhaust. Remember, try not to overuse it, if the enemy is too far away, it is better to let him go, save your ult and gank again later. On the other hand, in the early stages, hammer your enemy with anything and everything you need to in order to help your allies get a kill. Early on, it is a good use of your ultimate.

Ultimate @ team fights
Later in game, never use your ultimate on one person. It is just plainly bad. You have a spell that immobilizes the entire enemy team, do not waste it on one person.

Also, many amumus use their ult as an initiate. It goes like this: bandage toss -> ULT! Now most of the time that is also bad. Let me explain why:
You walk in front of your team, then you bandage toss even further away and immobilize all your enemies for 3 seconds. Your team sees you engaged and they rush after you - getting there the very moment your enemies get free again. Congratulations, you have just dealt 200 AoE damage and wasted a brutal disable, allowing your team to most likely get slaughtered.

What you want to do is bandage towards the enemy team and exhaust one of them, or otherwise slow one of them to force him to lag behind if his team continues retreating. Then, they either retreat and lose that person, or engage you, meaning you can ult just when your allies are close, turning your ult into a deathtrap.

In short, do not ult single people in later stages AND never ult when your team isn't there.

Here it is, guys! Tell me what you think about my amumu build, i will be happy about all comments as long as they make sence (meaning i will not be happy about the usual "omg noob kage's lucky pick" ****).

So, be reasonable guys, and if you dislike my playstyle, tell me why and make sence - and i will appreciate that.