I decided to make this guide to see what can be done when focusing heavily on AOE. Teemo seemed like a good choice for it because Ruunan's Hurricane procs his poison.

The AD marks and quints give you extra early aggro. The seals and glyphs give you defenses that WILL help you.

Simple enough. Standard 21/9/0 AD build.

Opening up with boots and 4 pots will give you early game sustain to keep your farm strong.

With all the attack speed you're going to be building you need some AD, and that's where BF Sword comes in. The early power this can give you will be ridiculous.

Berserker's Greaves will be your first real pump of attack speed. It doesn't seem like that much of a boost right now, but that's okay because you'll be getting a lot more AS, and the movement speed here is invaluable.

Ruunan's Hurricane is THE core item of the build. It gives you a HUGE boost in attack speed, deals bonus damage, and applies Teemo's poison, and the slow from the yet to be obtained Frozen Mallet.

Avarice Blade gives a nice crit boost and a gold boost you'll enjoy until a bit later.

Giant's belt gives you a little less sustain and upgrades into Frozen Mallet. If you have the gold when you go to purchase this, Phage is a perfectly Viable alternative, but if Belt can be obtained a bit earlier and gives you significantly more health.

Say goodbye to your greed and hello to lightning. Statikk Shiv boosts both your speeds and your crit chance. With the speed you have now, you should be able to make solid use of the lightning ability to farm, grab buffs, and be of good use in team fights.

And now we come to Frozen Mallet. The slow on this guy will come in great use for team fights when you factor in Hurricane, and the attack and health boosts aren't something to sneeze at.

Infinity Edge...this is what your BF Sword has been waiting for. This is the pinnacle of AD power. It gives you a huge power boost, and drastically improves your crit chance. Not only that, it gives a boost to your crit damage.

The final item in the build is the infamous Phantom Dancer. This badass little item right here is going to drastically increase your damage output yet again. It increases your movement speed, which is nice, but that's not all. It lets you MOVE THROUGH UNITS. Never be cut off by a tank again! This thing right here even increases your attack speed by a walloping 50%. Now watch those AOE items explode from you like nobody's business. The Phantom Dancer does one more thing for you too! It increases you crit chance by another 30%. That means you will have a 75% chance to crit each time you attack, which is a lot. The Phantom Dancer does all this for the low low price of 2800 gold.