Teemo - The Undefeatable
It seems to me that Teemo is the best champion in the game. Not because he's OP, but because people instinctively think that small means weak. He is also a beast both early game where he scares like no other, and late game where he can kill ANYTHING.
The other nice thing about Teemo is that he is an incredibly flexible champion, every build works on him, making him good for professional players to experiment with, and for new players to learn.
Skills
Camouflage
(Passive): If Teemo stands still for 2 seconds without taking damage, he becomes stealthed (damage will break this effect). Moving or taking actions will break Teemo out of stealth and give him Element of Surprise, increasing his attack speed by 40% for 3 seconds.
Blinding Dart
(Active): Obscures an enemy's vision with a powerful venom, dealing magic damage to the target unit and causing all attacks to miss for the duration.
* Cooldown: 8 seconds
* Range: 680
Cost: 70 / 80 / 90 / 100 / 110 Mana
Magic Damage: 80 / 125 / 170 / 215 / 260 (+0.8 per Ability Power)
Blind: 1.5 / 1.75 / 2 / 2.25 / 2.5 seconds
Move Quick
(Toggle): Teemo scampers around, increasing his movement speed. If Teemo gets hit by a champion or turret while Moving Quick, he gets knocked out of it.
* Cooldown: 8 seconds
* Cost: 40 Mana to activate
Movement Speed: 15 / 20 / 25 / 30 / 35 %
Toxic Shot
(Passive): Each time Teemo deals damage to an enemy, he will poison the target, dealing damage on hit and each second for 4 seconds. Magic Damage on hit: 9 / 18 / 27 / 36 / 45 (+0.14 per Ability Power)
Magic Damage per second: 6 / 12 / 18 / 24 / 30 (+0.14 per Ability Power)
Noxious Trap
(Active): Teemo places a trap which stealths and arms in 1.5 seconds. It detonates if an enemy steps on it, dealing magic damage and poisoning nearby enemies. Poisoned enemies take magic damage and have their movement speed slowed for 4 seconds. Traps last 10 minutes. Teemo gains a "stored mushroom" charge every few seconds. Maximum three charges. Each cast requires and consumes a charge.
* Range: 230
* Cooldown: 1 second
* Collision Area of Effect: 20
* Explosion Area of Effect:
Cost: 75 / 100 / 125 Mana
Magic Damage: 250 / 475 / 700 (+0.8 per Ability Power)
Charge Receive Time: 30 / 26 / 22 seconds
Slow: 30 / 40 / 50 %
Ability Guide
This may not be perfect, as each situation calls for different skillsets, but this is usually what I do and it works for me.
L1: Toxic Shot (1)
L2: Blinding Dart (1)
L3: Move Quick (1)
L4: Toxic Shot (2)
L5: Blinding Dart (2)
L6: Noxious Trap (1)
L7: Toxic Shot (3)
L8: Blinding Dart (3)
L9: Toxic Shot (4)
L10: Blinding Dart (4)
L11: Noxious Trap (2)
L12: Blinding Dart (5)
L13: Toxic Shot (5)
L14: Move Quick (2)
L15: Move Quick (3)
L16: Noxious Trap (3)
L17: Move Quick (4)
L18: Move Quick (5)
Items
As I said before, Teemo is incredibly flexible, and can work with almost any item set. This is the one I designed for general DPS to all champions. I'm going to outline them in order, and elaborate on the reasons why later.
Berserker's Greaves
Malady
Wit's End
Phage (Can upgrade to Frozen Mallet later, although it only improves his tanking)
Bloodthirster* (Optional, can be replaced with any good +damage item)
Infinity Edge
Since Teemo has naturally high Attack Speed Growth, we don't need to worry too much about giving him attack speed with his items. The items we do give him with +attack speed always have other good buffs that make them worth getting. The explanations for the chosen items is as follows.
The Greaves are great because they improve your attack speed and move speed early game, which is useful since Teemo is a run-in-run-out champion. In a nutshell, AS and movespeed. (From here on in I will abbreviate Attack Speed AS)
Malady is a beautiful item, proof that the whole is more than the sum of it's parts. Same AS as a Recurve bow, but has lifesteal and one of the best for the price passives. Every hit you deal will deal will cause the target to take an additional 6 damage stacking up to 6 times. Meaning numbers are just going to be flying off of your target's head. In a nutshell it improves AS, Damage, and gives Lifesteal.
Wit's End is was one that after a little thought, I decided needed to be here. Gives Magic Resist and AS, but has another great passive for the cost. Removes up to (usually always is) 42 mana from the target per hit and the target takes additional damage equal to how much mana you stole. In a nutshell, good AS, slight magic res, and 42 extra damage per hit, and can easily cripple casters.
Phage I put on here because it's just a good item for ranged DPS. It is a fairly inexpensive item, and it improves you in a lot of ways. For one, it increases your damage, allowing you to do more damage/second. It also increases your HP, making you much less squishy against mages. (I say mages because Blind Dart makes you practically immune to everything else.) The real reason you buy it is because it has a 25% chance to reduce the targets armor, and slow their move speed by 40%, meaning finishing off and chasing champions becomes a lot easier. In a nutshell, HP, damage, and chasing abilities. EDIT: Another alternative is to upgrade this to a Trinity Force as opposed to getting Bloodthirster and IE.
Bloodthirster is, as I said above, optional. This build is mainly comprised of the items you already have (Malady, Wit's End and Phage), so the other two spaces are for damage. I single out the Bloodthirster from the other damage items because it has lifesteal, and I admit to being a sucker for lifesteal. It also has great damage and increases in power for each kill you get, and farming is something Teemo rocks at. In a nutshell, great damage and lifesteal that improves with kills.
Like I said in the Bloodthirster description, the last two items to get are mainly debatable, but again I single out one. Infinity Edge is a massively useful item, giving you a whopping +80 attack damage. It also gives you some ludicrous critical hit chance, and the unique passive makes you win at life. When you get a crit, it does 250% damage instead of 200%, so when you're critting once every three hits and you attack twice a second, that adds up to a little over a cubic ton of damage. The only problem I have with Infinity Edge is that you will never buy it, because it is (correct me if I'm wrong) the most expensive item in the game. Also, by the time you get it you won't be able to use it because you'll have won. In a nutshell, TONS of damage, great crit chance and passively causes you to win 250% more. EXPENSIVE!!!
Strategy
Same as basically every champion early game, play defensive and conserve yourself. You can both solo and dual a lane, although early on it is considerably easier to dual. As people find smallness as a weakness, they will think of you as easier to kill, so if you are dualing, the enemies will target you. This means that you must be EXTRA CAUTIOUS! If they are not ranged, or not longer ranged than you, feel free to farm some creeps with little fear, however, if they have a longer range than you be wary. Also, be very careful and on the lookout for early game ganks, as they can allow the enemy to progress far further in level than you, making it harder.
When you hit level 6, you should be close to getting a Malady. Use your shrooms to farm even more, and you should get gold like crazy. Also use them in the common entry points of stealth shrubs to put enemy champions on edge. Whenever you see a narrow space, place a mushroom there. Also, in some places on the map there are decorative mushrooms. ALWAYS place a mushroom on these places for the lolz. Once you get to level 8-10, farming and sticking to your lane becomes much less vital, and we come to our next point in the guide.
Killing Champions
The recurring theme of Teemo is to make the players on the other team dead and angry. Teemo is a short ranged DPS champion that can take on every champion 1v1. Anything relying on auto-attackfor damage will be decimated by Teemo's blinding dart and lifesteal. If a champion tries to run, you have move quick (and probably mushrooms to slow them). Any champion relying on spells will be incredibly squishy, and therefore cake for Teemo. His mushrooms allow for a special event to happen known as NERD RAGE, for they will control the map and kill any weakened champion. A Teemo with good damage and lifesteal can easily solo a Cho'Gath with over 5K hp. This is called a David vs. Goliath, and it is hilarious. By endgame, it will take two to three champions' ulti to take you down, and at least one of them will need to be a disabler. Teemo is the God of ranged DPS, for in time he gets good enough to crush worlds.
To actually KILL a champion as Teemo is relatively simple, but requires finesse and practice to master. Before you begin the battle, make sure that it is an even fight. No enemy towers close enough to save him, no teammates hiding waiting for gank, nothing that you can't take. 1 v 2ing is possible, but I recommend killing one than going back, than killing another if you are alone. If not, go wild, but keep yourself with enough HP to be able to escape. To initiate, use your Blinding Dart on the DPSer in the group (if there is a group), and plant a mushroom immediately behind you. This mushroom enables you to be able to retreat, or to be able to bait their friends and kill them all. Proceed to either pump them full of darts, or bait them out to a place where you can pump them full of darts. A place where you can pump them full of darts and shrooms are blocking the escape is even better. Auto attack until they drop dead, or until you need to retreat. It's that simple. Depending on who you are fighting or who shows up, you might need to retreat at different health levels. If it's a melee champion, than you can cut it pretty close. If it's a disabler, better safe than sorry. Since by mid-late game you will be doing massive damage per second, you only need to fight for around 3-4 seconds before one of them dies or they are forced to retreat.
This is by far the most important rule of Teemo that anyone will ever tell you. PAY ATTENTION TO THE MINIMAP! This applies for all champions, but as Teemo you MUST do this because your speed and shrooms allow you to be able to dominate the map. No need for Clairvoyance or wards when you have an ultimate like Teemo's!
I hope this guide has given new players a chance to excel at a champion, and professional players another build to try out. I hope I was informative enough and that anyone, regardless of skill or experience, will be able to read this guide and go 30-nil.