This guide is geared toward the under estimated Teemo. AD/AS with chasing ability, but also escape-ability. Teemo is an annoyance in lane, so I don't recommend taking him mid unless merited.

The runes used are Armor Penetration Marks and Quintessences to give you that early game edge, and to avoid having to build it later in the game. Armor Seals and Magic Resist per level Glyphs will keep you alive through the early game harass and give you sustainability late game. You can substitute Magic Resist for Magic Resist per level if necessary.

The masteries are quite self explanatory, 27 points on offense, for the nice benefits for farming early game, and the edge late game. 3 points in defense for the extra armor needed late game to pick up where the seals leave off, gives you extra sustainability, and the ability to edge around team fights without getting picked off too quickly.

The whole effect of "You won't escape", comes down to the three core items. Boots, Frozen Mallet, Phantom Dancer. The Infinity Edge is for the 250% Critical and the extra attack damage.

While you'll have an excellent early game if you can farm decently, your late game will excel once you get your Frozen Mallet, Berserker's Greaves, and Phantom Dancer. Make sure you get your Infinity Edge after your first Phantom Dancer to keep up with the pace of the game.

Your early game farm is one of the most important things for Teemo. Avoid laning with someone else who requires heavy farm. Encourage your team to do do dragon whenever possible if you're laning down bot.

PROS to playing AS/AD Teemo:
•Chase your enemy down for the kill (Unless it's Singed)
•Clean up after team fights quite nicely
•Once fed, you're an unstoppable carry.
•Golem buff is nice to have, but not required when playing Teemo in this style.

CONS to playing AS/AD Teemo:
•Your mid game will fall a little behind if under-farmed.
•You still have a global taunt. (Teemo appears, 5 champions close in on him).

For summoner spells, I take Ignite, for the clean up, and Flash to escape, or catch up (Usually only Master Yi, or when entering a late team fight).

Now, you can take Exhaust, in place of either which isn't too bad of an idea. Slow down the enemies attack speed, move speed, and overall damage output, sounds pretty nice. So it's totally your call.

Avoid Ghost
Avoid Clairvoyance
Avoid Surge
Avoid Heal
Avoid Clarity
Avoid Smite
Avoid Promote
Avoid Cleanse
*Dominion only*
Avoid Garrison

The overall summary, Chase, Kill, Run.

Teemo is an excellent Clean up champion, and an excellent melter.

Use his Mushrooms to your advantage, if you feel you're going to lose the fight, head to the nearest bush, and place a mushroom, but keep running. If they've chased you and you feel you can win, continue to fight. Otherwise, you're alive now, and can recuperate for the next fight.

I love constructive criticism, so feel free to leave positive and negative feedback. <3

Much luck to those who use this build. :3