Not Updated For Current Season
I hope you enjoy.
Ghost and Flash. Why? Kog'maw has a problem, he is terrible escaping from fight when he needs, those spelss can easily help him to escape and can be easy used to attack.
This build makes kog'maw kill easily, so, mostly of the masteries are in attack, critical chance and armor ignore are important.
Utility are to mana regen, kog'maw need mana regen because ofter he needs to flood his ultimate, and mana it's a big problem here.
Mana regen as i already said, it's reallt important, attack speed and armor penetration for early game will help you a lot. If you like to change the Quintessence to attack speed it will work pretty fine too.
Your main skill is BAB (BioArcaneBarrage). Why? Use it often and you will do fine playing with Kog'Maw. So chhose it first.
Void ooze i choose second because can help you to slow your enemy and u can easily nuke him with the BAB and it does a very good damage early game. Second.
Caustic Spittle is the third. Why? You will start the game with a lot of attack speed with those runes, so you dont need at the begining of the game. But when you get leve 3 and this skill, it's time to be more agressive against your lane enemy, you attack fast, you can slow and the BAB does great damage against everybody.
First of all, 3 Doran blades will make you more durability in the battlefield, you will do a better damage and the 9% of life steal isn't bad. Off course that you will seel doran's blades when you need space fr the other itens.
Start with one doran'ss blade and a helth potion.
Go to base when you got 1.3k of gold.
Now you can buy 2 more doran's blade.
The next time you go back to base you buy the Recurve Bow.
With the recurve bow you are already pretty strong, can easily kill some enemy champions ganking. Use you slow.
Now you should buy Pickaxe, but if you can wait to buy all the Madred it will be better, the pickaxe wont be great difference to you, but the Madred Bloodrazer will, be sure about that.
With the Madred Bloodrazor you are strong, it's time to win the game, Gank and farm to buy the zeal and the Phantom Dancer. Later another Zeal and another Phantom Dancer.
When you finish both Phantom Dancers you will be really strong, with the Infinity edge your damage will be really huge with the critical chances and damage.
Bloodthister will make you more durability in the battlefield, lifesteal with 80%+ of critical chance isn't bad, actually it's pretty good.
Finish your build and start buying some elixirs.
You are now a killer, you kill killers and fighters very fast, like 1 or 2 seconds, and use the BAB range here. Tankers will fall in your front fast.
Any kind of help, revies of this build are welcome.