Kog Maw is one of the greatest DPS characters of the game, both AD and AP.

- The blue runes can vary. I chose to use CD reduction simply because you can't really go wrong with them. You can also get MP-5 runes if you want to harass more.

Greater Seal of Vitality - The HP yellow and quints greatly increase your survivability to gank/asassinate early game. By level 6 the per level yellow HP runes will give more HP than flat ones.

Greater Mark of Desolation - The red armor pen also helps kill early game with the Dusk-bringer -> auto-attack combo (not really a combo...)

Flash - One of the best skills on every carry, this greatly improve your getting in and out and escaping (that's what she said).

Exhaust - Helps Bio-arcane Barrage hit more, not to mention you can use it to escape.

Ignite - The extra damage is pretty useful but exhaust will allow you to land more hits and your physical attacks will always end up greater than ignite

Ghost - increase in survivability isn't bad, can also improve ganks.

Heal - NO

Revive- Initiate a team fight, die, revive, rush back to the team fight...I hope you realize I'm joking by now...

The passive is extremely useful

Passive: Increases Kog'Maw's attack speed. Active: Kog'Maw launches a corrosive projectile which deals magic damage and corrodes the target's armor for 4 seconds.
Passive: Increases Attack Speed by 10/15/20/25/30%.
Active: Kog'Maw launches a corrosive projectile which deals 60/110/160/210/260 (+0.7) magic damage and reduces the target's armor by 5/10/15/20/25.
Cost
60/60/60/60/60 Mana

The greatest asset of Kog Maw...Max ASAP
Kog'Maw's attacks gain range and deal a percent of the target's maximum health as magic damage.
Kog'Maw's attacks gain 130/160/190/220/250 range and deal additional magic damage equal to 2/3/4/5/6% (+0.01)% of the target's maximum Health (Max: 100 Damage vs Monsters). Lasts 6 seconds.
Cost
50/50/50/50/50 Mana

Slow for using Bio-Arcane Barrage
Kog'Maw launches a peculiar ooze which damages all enemies it passes through and leaves a trail which slows enemies who stand on it.
Kog'Maw launches ooze which deals 60/110/160/210/260 (+0.7) magic damage to enemies it passes through.
Additionally, it leaves a trail which slows enemies by 28/36/44/52/60% for 4 seconds.
Cost
80/90/100/110/120 Mana

Super Range ult that can finish off what thinks escaped
Kog'Maw fires a living artillery shell at a great distance dealing damage and revealing targets. Additionally, multiple Living Artilleries in a short period of time cause them to cost additional mana.
Kog'Maw fires artillery from a great distance. After a short delay, the artillery falls dealing 80/120/160 (+0.3) magic damage and reveals targets for 4 seconds (deals 150% bonus damage to Champions).
Each subsequent Living Artillery in the next 6 seconds costs 40/40/40 additional mana (Max 200).
Cost
40/40/40 Mana