Teemo Build Guide by
Not Updated For Current Season
This build is definitely an assassin build. You want to wait by a mushroom in stealth then when they are in range, attack with your 2.5 attack speed and depending on what their armor and magic resit is you should be able to kill them with your poison from your 3rd ability and mushroom before the buff wears off.
If you'd like instead of getting a second hextech gunblade you could pick up a black cleaver if they stack armor. Also you can switch out your boots for boots of swiftness, berserker's greaves or boots of mobility, depending on your play style of teemo.