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.
So this is just how I build my Teemo, I am not trying to step on any toes or hurt anyones feelings by this build, so don't complain if you don't like it. This is just how I build my own personal Teemo and I am certainly not a pro, but I try.
Th reason I do all heath runes is so that I have a much higher survivability in the beginning. As far as I can tell, having AP runes in the beginning is kind of a waste, because of the amplifying tome. I am trying to make Teemo less squishy in the beginning, but not sacrifice AP.
OK. So, if you look at a lot of other Teemo builds, you will see that they take toxic shot at first level. I really do not like this. Blinding dart does a lot more damage at first than toxic shot. Plus, you have the fear factor of taking a sizable chunk out og you enemies health bar.