Welcome to my first build, for one of the first champions I ever played on League of Legends, Teemo. Now looking at the title, you may have already dismissed this build, however, hear this build out, try it in a game, and see what the results are and you may be surprised, and please leave a comment below, I will appreciate your opinions.

Pros:

Fast Burst Damage
Quick Around The Map
Hard To Counter Against Late Game Unless Focused Down
Can Bring Down Even Tanks Once Built In Seconds
It's Fun


Cons:

Needs Alot Of Farm
REALLY Squishy
Hard To Recover If Struggling
Can Be Focused Down Easily
Does Require Some Stategic Play

Teemo has alot of potential in most roles, he can support his team using his ulty to scout, he can be an AD carry down bot lane, or he can do the most damage with his poison as AP, but Teemo hybrid can be one of the most devastating things you could face on the field of battle, because once he stops, it's hard to stop him.

Now the items are a bit of a mixed batch, you start looking at the build and think this is mainly AP, but then he's thrown AD items at the end. This build focuses down on the potential of both, by using the poison early game to cause a bit of burst damage to poke with, but slowly building up attack speed to further increase this damage, and then adding more AD items at the end so most champions will go down if he is given the chance to get that far.

Boots and Potions:
Early game, you will be taking and dealing damage, and you will want to try and avoid as much of that damage as possible, so being able to poke in and get out before they can hit you, is a great use, while the potions let you remain in lane for longer.

Daggers Leading Up To Malady
The attack speed for the malady should be essencial, for getting in more hits to last hit those minions, and finally when the malady is complete, you have a nice amount of attack speed AND AP to boot, not to mention a great passive that will help out further down the line.

Mercury Treads:
We are already going to have more then enough attack speed, so what we need is as least amount of time spend in stuns and snares and other CC's as possible, so we can get more of a chance to run away.

Stinger into Nashor's Tooth
Building into more attack speed, you slowly start to see how much damage you can deal before someone can start to be a threat to you, but the tankier the opponent, the harder it's going to get. By this point we will need more map awarness and our Blinding Darts up more, so the CD from the Nashor's Tooth will greatly assist us here and grant us a bit of mana regeneration to boot.

Recursive Bow Into Madred's BloodRazor:
The other item's aren't too ecential, by this point your dealing enough damage at a high velocity you won't need a normal Madred's, so more attack speed to inflict more poison upon your foes should be focused on, and once this item is complete, Teemo start's coming into his own, dealing high damage at a fast rate of attack with the passive from the Bloodrazor at his side.

Phage Into Frozen Mallet:
If you've made it this far, things are most likely going well for you, but now it's time NO ONE ESCAPES FROM TEEMO! getting a phage will grant you that slow on your basic attacks, and then upgrading it to the Frozen Mallet, increases this chance AND gives a niec HP bonus to boot, meaning this Teemo is no longer going down without a fight.

Wit's End (Final Item)
Making it this far means you've at least survived long enough to fill enough champions with poison to last several lifetimes and you should be congratulated, but you are still taking high damage from mages since you can't blind their spells, but with this, I doubt that will be happening for much longer.

"WHAT?!! Both ghost and Flash?!"

YES! God almight YES, when your as squishy as teemo and are being focused all the time, THERE'S NO TIME TO STAND AND FIGHT, YOU RUN AS FAST AS YOUR LITTLE YORDLE LEGS WILL TAKE YOU!
Your Move Quick's Passive won't save you if your being hit, and by that time, activating it probly won't save you, so that's where flash and ghost come in. Not only does it allow you the distance between your pursuers, but it also doubles up and a hunting down method.

Let me give you an example:

Say your being chased by a Blitzcrank, who has just managed to grab you and pull you into his fists, then a enermy Xin Xhao comes out the brush to come help kill you, YOU GET OUT OF THERE, using flash to create enough distance to safetly activate move quick, so that you won't be CCed much more, and get to your fellow team mates. Finally you reach one, let's say for instance a Dr. Mundo who was top lane, but they have already started running, TIME TO CHASE, but your move quick is on CD. GHOST TIME! Knowing that your now with a team mate who can easily protect you from some of the hits, your movement speed can easily hit them, and you can safetly Blind Xin Xhao without too much fear of being CCed by blitz and then get the kill.

That's just an example, but alternating between one and the other for chasing AND running, is what helps build up the kills for a teemo while making sure he can stay in lane to farm because he's avoiding most of the dangers from the enermy team.

The main trick here however to make this work is secure either solo top or bot lane, since you will need that farm to get the items in time to deal with the enermy team. Teemo is by nature a squishy character, so if your damage can't kill them before they kill you, your as good as a free pot of gold to them.

Against an enermy carry, you can take them down because you have an edge, Blinding Darts. These things will ensure you can kill them before they even get a chance to do any real damage to you, because you will have shot them 10 times before they have even hit you once, and 10 level 5 poison darts HURT.

If however, your finding yourself running away from junglers alot, at level 6, you can turn the tide with some cleaverly placed mushrooms in bunched up areas where you are laning. Warded choke points where the enermy WON'T run into them till they are chasing you, will give you a heads up and about a 2 second head start on running, be it away from them or to kill them.

This is my first build, so I would like to thank you for reading it, and I will try to update this as much as I can, alot is missing, such as screen shots, match results for this build, potential Videos and overall a Pro Guide Feel, but your comment's will be appricated and please make it constructive if you can because I want to imrpove upon this as much as possible. Happy Teemo-ing