Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Teemo, Drugs are Bad Build by AnatomiK
This build focuses on Abiltiy Power and magic pen, aswell as a little attack speed so that your poisons and mushrooms tick for alot.
Now for this build you must play very smart, meaning you must place your shrooms in places you think the enemy will go, ideally you want to be able to lead enemies into your shrooms as much as possible.
Never stay an fight unless you are 100% positive itll work out in your favor, this build is not a sit there and attack attack attack build, its a attack a couple times then try to bait them into your shrooms style build.
There is always the possibility of enemies not getting hit by shrooms, which either means A) They have outsmarted you and you must adjust your playstyle to outsmart them, B) Your doing it wrong, or C) Your putting shrooms in untraveled area's.
If you play this build correctly you should be an MVP on your team.