Teemo, especially with this build, can lead a competent team to many victories. This becomes more true in longer games when Teemo has provided unparallelled map control with Noxious Traps. Because of the accumulating worth of those toxic wards, even games with poor starts can be turned around for epic comeback wins. Additionally, with this build, Teemo becomes very useful in team fights later in the game (contrary to the common critiques he receives in this regard).

Throughout most of the game he is capable of winning duels with most champs or simply getting away. When he is moderately farmed by the late game Teemo contributes heavily to team fights with 2 strong slows (not counting the serious slow from Noxious Traps), a blind (which is especially devastating to AD auto-attackers), and incredible burst damage (on top of incredibly powerful poison from his Toxic Shot). And did I mention his Noxious Traps providing the best map control in the game?

This guide recommends that Teemo be played as a mid-lane hybrid AP carry. He can be useful in any lane, but for a few reasons he is best in mid. For starters, when he starts laying his Noxious Traps they are best utilized by providing control over the center of the map. Laying Noxious Traps in the corner lanes doesn't help spot when the enemy team is moving across the map from one side to the other. Also, his range and mobility allow him to solo a lane effectively while harassing the enemy player and getting last hits. There are some enemy champions that can counter him fairly well and force him under his tower, but effective ganks from his jungler can quickly even the playing field.

As for going AP hybrid... I feel it's the only way to play him. Some people will say that pro X uses an AS/AD build, but I'd suggest such pros are able to do that simply because they are excellent players -- and not necessarily because they are building Teemo in a efficient way. Three of Teemos abilities ( Toxic Shot, Blinding Dart, and Noxious Traps) all scale very well off of AP items and are largely wasted without. The only reason I don't build Teemo completely with AP items is because Wriggle's Lantern has so much utility for the price and because Hextech Gunblade offers the same (as explained later). Additionally, by starting with a little more attack damage it's possible that the enemy won't notice when you've switched it up with your end-game AP items.

Pros

He can last-hit fairly well (even while harassing).
He has some pretty good crowd control (with this build) by the end game.
He has some excellent burst potential (with this build).
He is FAST! With Move Quick activated he can even outrun a lot of players using Ghost.
Shrooms! Wards that damage for up to 1000hp (and slow) give preeminent map control.

Cons

Starts off pretty squishy (which I address with Quints of Fortitude).
Susceptible to CC (which means you should keep your distance).
Noxious Traps are somewhat countered by Vision Wards & Oracle's Elixir (KILL THE ORACLE!).
Blue Buff dependent (to continuously lay wards and still be able to blind).
Ends up pretty squishy (he shouldn't fight in melee range).

Camouflage

Ok, I'll admit it, his passive is the one thing I find to be a bit lacking. Most other Teemo guides admit the same thing. Some people suggest that it's good for cloaking when he's being chased, but that can be A) hard to time, B) it basically stops him from doing anything else, and C) it hopes they don't have true-vision wards or Oracle's Elixir (did I mention that your team should hunt down any enemy with Oracle's?). It's primary utility, in my opinion, is in getting first blood by rushing out to a lane and cloaking while a teammate pretends to be laning there or hides in the bushes. And while that can be quite effective, it's doesn't always work out and then... Camouflage doesn't have much further use in my opinion. You could try that tactic again later, but there are risks as mentioned.

Blinding Dart

This ability offers some great harass potential while laning and can also cause your opponent to miss some last hits. It is especially useful against auto-attackers throughout the game and Tryndamere's rage not because they are undying. With enough AP it becomes a pretty powerful nuke later in the game. The real fun starts when you add Rylai's Crystal Scepter and get a slow to go with the blind. This blind is, somewhat counter-intuitively, probably part of Teemo's global taunt.

Move Quick

How do I explain this ability and what it's good for? Well, it makes Teemo move very quickly. It can be used for everything from getting back into the lane after shopping, to chasing, to fleeing, and for generally getting anywhere Teemo needs to be. This ability makes Teemo have the highest average move speed in almost every game. It doesn't stop collision, but it's practically like Ghost with a shorter cooldown.

Toxic Shot

This ability makes Teemo almost seem sinister. It helps to last hits but it's best usage is when enemy champs don't fully appreciate the DOT effect as you keep shooting darts into them with your blowgun. Then, when they realize they need to run, you often get kills when they are out of your vision. It's not so important to get AS for this ability since it doesn't stack (unlike Twitch's poison) but when you get some AP it become pretty devestating.

Noxious Trap

This is part of what makes Teemo so fun to play and so useful a member to any team he is on. It's also probably the one thing which separates the good Teemo players from the bad. While you can constantly generate more of these to place around the map, you can can only carry 3 at a time. This means you should be dropping them constantly in the best close place you can find.

Ideal locations for them are in just about any bush, at lane entrances, around Dragon, and around all buffs. The more you play Teemo the more you'll get an idea of where these can be useful at any particular point in the game. In addition to providing general map control, they are great to place in escape routes -- either for your team to fall back across or to slow down an enemy whenever they might try to flee. Auto-pathing is also something to consider in that last regard. Placing these shrooms in the right places will allow you to get many assists and kills when they trip up a fleeing opponent. Nothing causes enemy players to rage more at Teemo than well-placed Noxious Traps. And you're teammates will often get a good laugh when you get a multi-kill while respawning. This is definitely part of Teemo's universal taunt.

Beyond warding key locations... Noxious Traps can be used directly in team fights or to farm. Like constantly planting them, I find using them for these purposes to require a bit more skill. For farming, you only want to place them in a large group of stationary creeps. You don't want to place them in the middle of the lane and let them explode on just one or two creeps (that's a real waste). In team fights, using them can be tricky because to hit directly you have to be in melee range and it takes second for them to go invisible and activate. By that time your enemies may have killed you and backed away from the location. Often I prefer to plant them around the edges of a team battle in case my teammates suddenly need to flee. In team fights, like always, you still want to keep dropping them constantly -- even if you just drop them right at your feet no matter where you are.

Using the full item build in this guide will make Teemo's Noxious Traps do about 1000hp worth of damage over the course of 4 seconds and will initially slow enemies by 65% (thanks to the additional slow from Rylais's Crystal Scepter).

Although they only last ten minutes, the Noxious Traps will be practically everywhere by the end of the game if you drop them constantly. But this is dependent on two things which are somewhat out of your control. The first is blue buff. Teemo really this buff to keep planting shrooms and still be able to use blinding shot in fights. This requires some coordination with your team (assuming they want total map control with Noxious Traps). The second, is Oracle's Elixir. Oracle's Elixir is the bane of every Teemo. And just as Teemo has a universal taunt (for reasons which no one may fully understand), Oracle's Elixir is the ultimate taunt to any Teemo player. Of any kills that may occur during any given game, killing a champion with Oracle's Elixir activated is always particularly satisfying. Unfortunately, these kills may also require coordination with your team -- especially if it's being used by a tank. Noxious traps can provide a game-breaking benefit to any team that fully appreciates their vigilant and proper placement. However... if you are constantly denied blue buff, or if the tank with Oracle's is allowed to survive, Teemo's usefulness is seriously hampered.

Noxious Traps > Toxic Shot > Blinding Dart > Move Quick

This is where I suppose some points of contention might arise, but my suggestions here are actually pretty standard in relation to other guides (as admittedly much of this guide is). The best Summoner Spells for Teemo are Ignite & Flash. Ignite, in my opinion, contrary to what others seem to say, remains useful throughout the game as part of Teemo's burst combo ( Blinding Dart [with Rylai's slow effect], Hextech Gunblade's active [with it's slow effect], and Ignite [which deals 410 damage at max level and synergizes well with Toxic Shot's DOT]). Flash is great for Teemo because it gives him a secondary escape mechanism (in addition to Move Quick's active). These two seem by far the most practical Summoner Spells for Teemo and I'll stand by that.

One spell in particular which I feel would be wasted on Teemo is Ghost. How fast do you need him to move?!

Ok, here we go, more contention. But like I say... these are generally pretty standard but I am mixing it up a little and trying to offer a more comprehensive reasoning for getting these items than I've seen in other guides. Also, as I mentioned earlier, I feel AD builds waste a lot potential for Teemo -- despite what more skilled players with worse builds might suggest.

I like to start out with Cloth Armor and 5 Health Potion. This gives me some staying power no matter what is thrown at me and allows me to save up for my first trip back to the shop. On my first trip back I hope to have enough to upgrade the cloth armor into Madred's Razors and also buy Boots. A few more health potions on the first trip back is also nice. Then I like to complete Wriggle's Lantern and Mecury's Treads on my second trip back. After that... I just basically get the items in my list ASAP.

Mercury's Treads

These boots are great for Teemo primarily because of the tenacity they offer. Teemo can move away from sticky situations fairly easily unless he is under heavy crowd control and these boots minimize those effects. It's still probably best to avoid being targeted by CC spells, but Mercury's Treads will help in this regard. Also, they offer some MR which is particularly useful since Teemo will often be going against a mage in the middle lane. Beserker's Greaves don't offer much assistance because Toxic Shot's DOT does not stack and we are not looking to maximize AD.

Wriggle's Lantern

This item offers Teemo a lot of utility and survivability at a good price. It makes last hitting effortless, gives him some sustainability with lifesteal, provides armor (which is always useful), and gives him a free sight ward which is just the icing on the cake in terms of the total map control which Teemo will eventually give. And again... this is all at a relatively inexpensive price early in the game. It can be replaced later in the game by Lich Bane (or many other items which will synergize better with his overall build later on).

Malady

Almost every Teemo guide suggests this item for good reason. It synergizes well with his Toxic Shot by stacking MR debuffs and remains useful throughout the game. This item really improves his early-mid game DPS and, like Wriggle's Lantern, is fairly inexpensive.

Hextech Gunblade

This item is what really starts to make Teemo dangerous in duels and team fights. Ironically, almost none of the other Teemo Guides (even the ones which suggest this item) talk about it's active. I guess they consider it obvious, but I think it's essential to Teemo's damage output. The active does 300 damage AND reduces the target champion's movement speed by 50%! This allows you to get in more Toxic Shot's if they try to run or it can be used to slow a charging enemy. When team fights are imminent it's nice to blast an enemy with this if they step too close so your teammates can jump all over them. AND, it gives you 20% spell vamp from itself (not to mention from Blinding Dart & Noxious Traps). The +40 AD and +70 AP add greatly to your overall DPS and the 15% lifesteal is just gravy. There are troll guides which suggest building Teemo with nothing but this item and boots.

Rylai's Crystal Scepter

This is where we finally start committing more heavily to strict AP items. However, not to be overlooked, is the 500 HP it offers to help make Teemo a bit less squishy. And last, but certainly not least, is the fact that it offers another more consistent slow to Teemo. Between this and the active from Hextech Gunblade... Teemo actually has a good amount of crowd control while simultaneously bursting down enemies. It also increases the slow on Noxious Traps to make them more effective.

Rabadon's Deathcap

This is the item which turns his Blinding Dart into a nuke, his Toxic Shots into cyanide, and his Noxious Traps into things which his enemies fear. This is the item which really adds the AP to AP/Hybrid. After this item... anything that Teemo hits you with will hurt, a lot.

In very late games I'd suggest selling Wriggle's Lantern and replacing it with Lich Bane or Morello's Evil Tome. The latter will add even more AP, some mana regen, and 20% CD. Alternatively, you might want to buy a more defensive item like Banshee's Veil or Frozen Heart. I'm generally fine continuing on in the belief that the best defense is a good offense and depending upon Teemo's Speed, positioning, and map awareness to keep him alive.

Masteries will prove to be another point of contention but I'm going to continue along the lines of promoting a good offense as the best defense. I feel that defensive and utility masteries will still leave Teemo rather squishy and the offensive masteries will give him a big boost throughout the game (from last hitting at the beginning to amplifying his massive output at the end).

Runes are similar to masteries insomuch as they aren't always very game breaking. However... every little bit helps and I pick runes largely to help in the early game. And I do actually differ from my offensive philosophy a bit by suggesting some early defense in the form of Seals of Resilience (+1.41 armor each). Next, I suggest Greater Marks of Destruction (+1 armor penetration & +.57 magic penetration). Glyphs of Insight offer some magic penetration (+.57) which synergizes well with Toxic Shot. And, finally, I suggest Quintessences of Fortitude (+26 HP) which will make Teemo much less squishy in the early going.

As I suggested in the title, and throughout this guide, Teemo is a team player. His team needs to appreciate the map awareness he provides, allow him to farm and secure the middle lane, feed him blue buffs, and kill of any enemy champions who have Oracle's Elixir. Beyond that, as with most champions, they need to form a solid team composition which compliments his skill set. For example... no one should expect Teemo to be the one to initiate a team fight with his blind.

A standard team composition, with Teemo in the middle lane, would look something like this...

A Tanky AP jungler -- Cho Gath, Amumu, or Maokai (for example)
An off-tank AD top lane -- Nasus, Garen, or Jarvin (for example)
Bottom lane AD ranged -- Vayne, Ashe, Caitlyn (for example)
Bottom lane support -- Sona or Soraka or Taric (no real alternatives)

I feel a team composition along the above lines would be a successful team. Furthermore, I feel like a team coordinating over a voice chat system (like ventrilo) could even beat a team stacked with more skilled players who aren't using voice chat.

In closing I feel that, in the interests of full disclosure, I should reiterate that I am not a pro. In fact, my terrible ELO has only just started to rise out of the gutter thanks to this build. I do, nevertheless, feel that this guide is as good as any out there (for beginners, at least) even as I must admit that there are inevitable similarities other guides (which actually serves to establish the feasibility of this guide). It is my hope that I have possibly spelled things out for people in a way which might help them understand Teemo more clearly. Maybe something was clarified that was previously confounding. Also... I would like to establish competitive a team along the lines mentioned in the team work section. If you have Ventrilo and could fill one of the mentioned roles, please contact me in game (Nihilo0). By the way, that's a zero at the end of my name. And that's my guide! I hope you enjoyed it and I look forward to any positive feedback or constructive criticism.

Never underestimate the scout's code!