I prefer Kog'Maw for slowing enemies, then push for a quick kill. This is extremely effective when you are with your team, especially when the have powerful AoE abilities (ex. Fiddlesticks Crow Storm).

The soul purpose for the rune build of Kog'Maw is to focus mainly on attack speed and attack damage. This will make 1 vs. 1 and 1 vs. 2 battles to be made easier.

The masteries build for Kog'Maw, like the runes, focuses strongly towards attack damage. Some minor inclusions are cooldown reduction, critical chance and damage, life-steal, and armor. The main purpose for cooldown reduction is to reduce the cooldown for Bio-Arcane Barrage. The critical chance and damage is for making fights quicker. Armor bonuses is for the soul purpose of surviving battles (and running away from them)

In the beginning of Kog'Maw's item build, attack speed is emphasized greatly. Once the build reaches the Bilgewater Cutlass, it's Unique Active can be put to good use. It's slow ability can be before using Void Ooze or after Void Ooze's effect is timed out. Once the Hextech Gunblade is purchased, the Active of the Bilgewater Cutlass's range is increased for 400 to 700, and the damage from 150 to 300. This ability makes a great item for enemy champions on the run. When Wriggle's Lantern is purchased, if Kog'Maw is being used for jungling, the lantern can be set up as a sight-ward (this lasts 3 minutes). When Phage is purchased, this will be an even more helpful tool for chasing enemies, especially with the chance of an enemy being slowed whenever an enemy is hit with a basic attack. Ionic Spark is very helpful when fighting groups of enemies and minions. By the time Ionic Spark is purchased, Kog'Maw's attack Speed will be at around 141.765 attacks per second. this will charge up the electric shock passive, dealing 110 damage to an enemy minion or champion, this shock will bounce to 4 extra enemies. Keep in mind that the bounces has a range capability of 400 units. Once Frozen Mallet is purchased it will complete the build, allowing 40% chance of slowing (15% greater than that of phage) and an extra 700 health.

The skill sequence of Kog'Maw us very important if victory is desired. Starting out with Void Ooze is useful for farming off of minions in the beginning since it fires in a line (with a range of 1200 units) leaving a trail of goo that slows enemies by 28/36/44/52/60% for 4 seconds. This also deals 60/110/160/210/260 (+0.7) magic damage to enemies that the shot passes through.

At level two, get Caustic Spittle. This will passively give a 10% attack speed bonus. When Caustic Spittle's projectile hits an enemy, it deals 60 magic damage and reduces the target's Armor and Magic Resist by 5 for 4 seconds. This gives a chance to deal some extra damage to your target

From here, the goal is to max Bio-Arcane Barrage as soon as possible. Level at levels three and four. Bio-arcane Barrage is Kog'Maw's most helpful ability. It increases the range of Kog'Maw's basic attacks, and deals extra magic damage depending on the enemies health. This ability lasts 8 seconds.

At level 5, level Caustic Spittle.

At level 6, level your ultimate, Living Artillery. When fired, after a short delay, the artillery falls dealing magic damage and reveals targets for 4 seconds (deals 150% bonus damage to Champions). This is especially useful for enemies out of range of your basic attacks. If an enemy is hidden in bushes or if they are out of few in the fog of war, casting this will help reveal small areas.

At level 7 and 8, level Bio-Arcane Barrage.

At level 9, level Caustic Spittle.

At level 10, max Bio-Arcane Barrage.

At level 11, level Living Artillery.

At level 12 and 13, max Caustic Spittle.

At level 14 and 15, level Void Ooze.

At level 16, max Living Artillery.

At level 17 and 18, max Void Ooze.

Once the ultimate ability, Living Artillery, is available, heaving champion attacking can begin. The combination of skills that should be used is as follows.

1. Hit the enemy with a Void Ooze attack (or the Bilgewater Cutlass/ Hextech Gunblade Ability) to slow the enemy target(s).

2. Activate Bio-Arcane Barrage.

3. Immediately attack with Caustic Spittle. (This will allow more damage to be dealt)

4. Once everything has been activated, use living Artillery (take note that every other Living Artillery used over the course of 6 six seconds adds an extra 40 mana to the spell cost)

There are a variety of different ways Kog'Maw's spells can be used.

Way #1

Revive and Teleport.

This way is very efficient for returning to a battle after death (obviously)

Way #2

Exhaust and Ignite

Kill em' KILL HE WHO RUNS FROM BATTLE!

Way #3

Heal and Flash

Used for assaulting enemies, and healing after or during a fight.

ALWAYS REFRAIN FROM ENEMIES THAT STUN, THIS IS KOG'MAW'S PRIME WEAKNESS.