Ok well I've been playing as Kog since he has come out about two years ago so I have got a very good idea how to build him.. I have gone through many different builds to come up with the ones I have displayed. I have seen many players think that they can just use AD to make a good Kog however, AD and AP are a small part of what you need to play a good Kog. You will need lots of atk speed to be successful because more attacks per second with AD will add up quickly especially with Kogs range.

For the Runes you will need, I recommend to pick up mainly Atk Speed runes. So I go with 9 atk speed glyphs... 7 atk speed seals with 2 AD seals... 5 AD marks with 4 atk speed marks... and 3 atk speed Greater Quints... this will give you a Level 1 attack speed of 0.88 add on the dagger and you start off with 0.96 as a Level 1 Kog. Right off the bat you almost have a 1 attack per second physical attack.

Like I mentioned in the Items section of the guide, you want to start off with the dagger because after you purchase that you have the option to get a ward, or keep what you have left and put that towards the boots that you can purchase with 500 gold.

After you get your boots, purchase the Long Sword to give you 10 AD, buying this also allows you to build into the Vampiric Scepter, this gives you 10% Life Steal... It doesnt seem like much but any life steal helps you especially early game.

After you get the Vampiric Scepter, purchase two more daggers, this leads into purchasing the Stinger which gives you another 40% of Atk Speed.

Next buy another Long Sword, and a Tear of the Goddess(this helps with the mana especially after you reach Level 6.) After you buy both of these items buy a Manamune.. Along with helping your mana regeneration and giving you more mana after each attack, it also builds more AD with the amount of mana you have, and after you get 750 additional mana from using the Manamune it transforms into Muramana and this allows you to go up to 1000 additional mana.

After you purchase the Manamune, buy another Long Sword and save up another 1200 gold in order to purchase the Zephyr. This item gives you 20 AD, 50% atk Speed, 10% Cooldown Reduction, and 10%Movement Speed along with 35% tenacity.

Next item that should be on your list is the B.F Sword. This gives you a massive boost of AD which is very handy when using the Bio- Arcane Barrage ability, after you purchase this 1550 gold item the bloodthirster is easy to get at only 650 gold. The Bloodthirster is essential to Kog's build because not only does it give him an additional 70 AD with a possible 100 AD it gives Kog another 6% lifesteal when the Bloodthirster is completely fed.

The Phantom dancer is the next item you should be working toward. To get this the first item you should buy is a Zeal for 1175 and another dagger. After purchasing both of these the price of the Phantom Dancer will drop to 1230. The phantom dancer is used for another 55% atk Speed and 30% Crit Chance with 5% movement speed.

The Last item that should be on your list can be either another Bloodthirster, if you find that you're still a bit squishy. Or if you find that you're running out of mana, buy another Manamune to help the mana situation and this also allows you to build more AD at the same time as you get more mana.

By the time everything is built properly, your final stats should be approximate to this

AD: 350+
AP: 0
ATK SPEED: 2.05+
MANA: 1995+

Make sure to pick up Bio- Arcane Barrage and max it as soon as you can, followed by the Void Ooze to be maxed next by Level 12. Living Artillery take it at Level 6, 11, and 16. and Caustic Spittle take it last because by the end of the game it helps with your final attack speed, but honestly you will probably never use Caustic Spittle in any situation unless all other attacks are on CD

Farming is something that is essential to building a good kog. You need to take out as many creeps as you can because the items you need are not cheap. Not to mention attacking creeps will also help build both your Bloodthirster and Manamune.

Team work is essential to keep you alive, especially early game. Try to go into the bottom lane with a tank or a strong support with a good stun. If you ally has a good stun you will have a very strong game. Allow your team mates to engage the opposition rather than you unless you are poking them with your Living Artillery. Kog has a good poke but make sure of your ganking lanes because its easy to get caught up trying to get the kills. Take as many kills as you need to even if you do end up KSing people. A fed Kog is deadly late game, especially with his range and his slow.