This is my first guide and I mainly made this guide because it is how I like to build AP Kog'Maw and I wanted to share it. The second build is my outdated utility spec build if anyone wants to look at it.

Early game this build is basically AP Kog'Maw. Snipe people with your rediculous range on Living Artillery and your Bio-Arcane Barrage is slow, but hits hard. Later on in the game, your living artillery still drops bombs while your Bio-Arcane Barrage eats huge chunks of health along with Lich Bane procs.

Please comment on this build as am open to suggestions. If you don't like this build please leave a comment telling me why, not just saying that you think this is a terrible build and a downvote. Any feedback at all would be appreciated.

PROS

Super long range harassment
Good supporting fire
Longest auto-attack range in the game (with Bio-Arcane Barrage up)
Can be very fun to play
Is super annoying to the opposing team

CONS

Moves very slowly
Squishy
No innate escape ablities
Dies easily if focused
Mana hungry early game

I used to use a utility mastery build, but I have found that it isn't as powerful as a basic mage mastery build (21/0/9), which I currently use. Basically, get everything related to AP in the offense tree along with the mana and mana regen from the utility tree. Also get Runic Affinity for blue buff.

Greater Mark of Magic Penetration - You do tons of magic damage...what else would you put for red runes?

Greater Seal of Scaling Mana Regeneration - Kog'maw is mana hungry, this gives you good mana regen.

Greater Glyph of Magic Resist - These give Kog'Maw some good MR if you are facing an annie or other magic damage as burst damage can kill Kog easily. You can also take Greater Glyph of Scaling Ability Power if you just want to give Kog'Maw some scaling AP. I don't take Greater Glyph of Cooldown Reduction because Kog'maw doesn't really need much CDR and his ult is already on a 1 second cooldown at level 3.

Greater Quintessence of Movement Speed - I take these because Kog'Maw is so slow. It really helps to have the extra movement speed for doing anything around the field. Alternatively, you can take Greater Quintessence of Ability Power.

Flash - I take this spell because Kog'Maw has no real innate escape ability and Flash really helps in that respect. You can use it to get away over walls or flash out of Nunu's ult, etc. It can also be used to get in range to get the shoot the last Living Artillery that kills a champion.

Teleport - I take this spell because Kog'Maw is very slow, so teleport can get you around the map much faster than just walking. Teleport helps when u want to buy something but you don't want to miss out on your farming and exp or it helps to get to a tower to defend. It can also get you to where you need to be for a team fight or you can continue the siege on the enemy base if you get hurt and need to go back for a heal.

Ghost - I personally prefer to take Flash as opposed to this spell because I find that moving instantly out of Nunu's ult or over a wall is better than moving faster.

Exhaust - This is a great spell, it can stop people from getting away, or it can stop a Yi from autoattacking you to death so you can get away or kill him. I personally prefer Flash and Teleport, but this is a viable spell too. I just find that if you are in range to use this spell, then usually you are too close anyway or just already dead in late game.

Clarity - This spells can help out early game as Kog'Maw has mana problems then, but I find that it is mainly just a waste of a summoner spell because it loses most of its potency late game, making it mostly useless.

Ignite - A good spell, but honestly on Kog'Maw I don't think that it is the best choice. Usually this is best used on a low health champ that is running away...but Kog'Maw can just use Living Artillery to the same effect and at a much longer range. Also it has the same problem as Exhaust: if you are in range to use this spell, usually you are too close. I could see it's use as a regen stopper against some champions, but I personaly don't think that this spell is worth it on Kog'Maw.

Heal - I could see this being useful...but thats why I buy Health Potion. It is also is mostly useless late game.

Cleanse - Same reasoning as to why I don't get Mercury's Treads, if you are cc'd, they you are probably already dead or you can still kill them first (or run away) without this summoner spell.

Clairvoyance - You already have Living Artillery, how much more bush check do you need?

Revive - Don't really think its useful on Kog'Maw.

Smite - You aren't a jungler, so why would you need this?

Surge - Not a bad choice for Kog'Maw as he uses both attack speed and AP, but I would rather take Flash and Teleport as I find that they have more utility than Surge and can help more overall during a battle or getting into a battle.

Promote - I don't like this spell on AP kog as he does not do much damage to buildings until you get a Lich Bane (late game), so I wouldn't take it as you don't generally want to push a lane by yourself, as he is vulnerable to ganks.

Core Items

Secondary Items

Optional Items

I start out with Boots and 3 Health Potion. The boots help with dodging, escaping and moving in and out for last hitting. The health potions let you stay in lane longer if you get hit a few times.

For the first time back get a Tear of the Goddess. This will help with your mana problems.

The next time that your are buying items, get Sorcerer's Shoes for the Mpen and speed; then the item order depends on what is happening in the game. Go for Rabadon's Deathcap if it is just a normal game, or for Rylai's Crystal Scepter if you need health more than AP. Get whichever you didn't get, buy afterward.

After getting those items, work on turning your Tear of the Goddess into an Archangel's Staff.

The next item on the list is a Lich Bane. It should be getting into late game by now, so after you get it, you should be doing 400+ damage from the proc alone.

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Boots - I used to get Berserker's Greaves for my boots because they were cheap and good, but now I go for Sorcerer's Shoes because the Mpen is better than some attack speed. I generally don't buy Mercury's Treads, because if you are caught in cc late game, you are usually dead already or it doesn't matter that you are cc'd.

I don't have a six item build listed because the last item can be used for whatever situational item you need. If they are getting major magic resist, get Void Staff, got an enemy Karthus taking out half your hp with his ult, get Banshee's Veil, ect. I listed a few optional items; if you feel that another one needs to be listed, just suggest it and I'll probably put it up there.

- (Innate): Upon dying, Kog'Maw starts a chain reaction in his body which allows him to move faster for 4 seconds and detonate at the end of the duration, dealing 100 (+ 25 x level) true damage to surrounding enemies.

One of the funniest passives out there. If you are going to die anyway, do as much damage as you can, maybe you can kill them with this after you die. Always hilarious to see some champion get killed when they can't escape after they kill Kog'Maw. Obviously don't try to get killed, but if there is no choice, go down fighting. If the enemy champion escapes after you die, run towards the nearest creeps, might as well get some gold if you are dead anyway.



- (Passive): Permanently increases Kog'Maw's attack speed.
Attack Speed Bonus: 10% / 15% / 20% / 25% / 30%

(Active): Kog'Maw launches a corrosive projectile at a single target which deals magic damage and reduces its armor and magic resist for 4 seconds.
Armor and Magic Resist Reduction: 5 / 10 / 15 / 20 / 25
Magic Damage: 60 / 110 / 160 / 210 / 260 (+0.7 per ability power)

Cost: 60 mana
Cooldown: 8 seconds
Range: 625


This attack is good for last hitting and does good damage when you get a decent amount of AP. If you are close enough, you can use it on an enemy champion before you unload your other attacks on them. This provides more magic penetration and armor penetration so you will hit them harder.



- (Active): For 8 seconds, Kog'Maw's autoattacks gain range and deal additional magic damage which is equal to a percentage of the target's max health. The damage caps at 100 against minions and monsters.
Bonus Range: 130 / 150 / 170 / 190 / 210
Max Health to Damage Ratio: 2% / 3% / 4% / 5% / 6% (+1% per 100 ability power)

Cost: 50 mana
Cooldown: 17 seconds


This attack increases your autoattack range to be the longest in the game when fully leveled up. It is good early game for harassment, damage, and range. Late game it really works well with all the AP that you have: each hit can do up to 13% of their health per hit; potentially 17% if you get a Madred's Bloodrazor (though your attack speed won't be very high with this build).



- (Active): Kog'Maw launches a projectile in a line in front of him which deals magic damage to all enemies it passes through and leaves a trail for 4 seconds which slows enemies who stand on it.

Magic Damage: 60 / 110 / 160 / 210 / 260 (+0.7 per ability power)
Cost: 80 / 90 / 100 / 110 / 120 mana
Slow: 28% / 36% / 44% / 52% / 60%
Cooldown: 12 seconds
Range: 1,000

The ultimate farming tool. This mid-game combined with Living Artillery will just wipe out creep waves. Towards the end of the game, you can just throw one of these at a creep wave and it will kill all but the very toughest creeps. This spell also has great uses versus other champions. Fully upgraded the slow is 60%, so it is a great tool to use to ambush, run away with, or just deal a lot of damage (with the 0.7 AP ratio it scales well). It can also be combo'd with Living Artillery to get the perfect shot or with Bio-Arcane Barrage to make sure that they can't get to you or run away.



- (Active): Kog'Maw shoots a living artillery shell to a target location at a great distance and falls after a small delay dealing magic damage to all enemies hit and revealing them for 4 seconds. It deals 2.5 times as much base damage to champions.
Each subsequent Living Artillery in the next 6 seconds after a cast will cost 40 additional mana, capping at 200 per cast.

Magic Damage: 80 / 120 / 160 (+0.3 per ability power) (+0.5 per bonus attack damage)
Magic Damage to Champions: 200 / 300 / 400 (+0.3 per ability power) (+0.5 per bonus attack damage)

Cooldown: 2 / 1.5 / 1 second(s)
Cost: 40 mana + 40 for each additional time cast within 6 seconds.
Range to Center of AoE: 1,400 / 1,700 / 2,200
Radius of AoE: 200


This skill has amazing utility and is a main source of damage for this build. It allows you to check bushes, as it reveals the area around where it hits (and enemies that it hits), harass like crazy with the rediculous range, and it makes sure that you still kill that champion that runs away with one health.

The only drawback of this spammable ult is the stacking mana cost debuff; if you are not careful of how much you use this spell, you will run out of mana very quickly. The 0.3 AP ratio is not that great, but it is amazing because it deals 150% extra damage to enemy champions and is spammable. Use this in combination with Void Ooze and you can farm like crazy.

Also, a good tip: even if shooting this into the brush doesnt actually reveal a champion and it doesn't hit a champion, giving them the "Kog can see you" buff, it will often target them. This means that even though they are not revealed and you can't see them, you know that they are in that bush and that you should beware of them.

Start with Bio-Arcane Barrage for the range boost and some extra damage for last hitting and general harrassing. Next get Caustic Spittle for last hitting and some good magic pen and armor pen if you have a good chance to gank. Then get Void Ooze third for help if there is an opportunity to gank, to escape a gank, or just as another attack and last hitting help (beware that it costs a lot of mana at low levels).

After that level up Bio-Arcane Barrage till it gets to rank 3 to get some good range on that ability for harrassing and last hitting. Then go for Void Ooze till it is maxed because it does good damage and helps hit enemy champs with your ult. Finish maxing Bio-Arcane Barrage to get your range up and then finally Caustic Spittle for good damage and magic pen. Of course, get Living Artillery when it is available.


Basically Living Artillery > Bio-Arcane Barrage (rank 3) > Void Ooze > Bio-Arcane Barrage (max) > Caustic Spittle

This build has a fairly weak early game (though, played right, can kill easily), but can be very potent mid and late game. It sometimes has problems with enemies that are very good at dodging or who can teleport and Kog'Maw has problems in general with enemies that have gap closers. End game is when this build really gets powerful: your Castic spittle and Void Ooze deal major amounts of damage and your Living Artillery has massive range and damage. Bio-Arcane Barrage is very potent in the end because with all the AP, it generally does 12% of hp per hit, which is + the Lich Bane proc, making you very dangerous from a distance.


Thanks Shayde97 for suggesting that I swap my RoA for a Rylai's, I was looking for something to replace the RoA and that fits perfectly.

Also, thanks jhoijhoi for making an awesome guide of how to make awesome guides. It helped on a lot of formatting ideas and general stuff to create a great guide.