Teemo is a teambased champion mid- and late-game, kills people early by himself. We have seen ap, hybrid and ad specs. ive tried them all and i liked ap, but it wasnt enought, so ive experimented with this build and its good becouse you can easily alone take down squishies and some bruisers (all depends on who where and when). you take down tanks in team-fights as they were candy, and you will get lots of kill/assist as long as you stay out of harms way.

You start of with a Regrowth pendant and a health pot, this will help you stay in the lane longer, as soon as you reach 700 gold you recall and upgrade your pendant to a Philosopher's Stone and buy Boots of Speed. after that you try to stay in your lane, and maybe do some ganking, untill you get 1850 gold to buy your Malady, Then just keep on ganking and pushing and buy all the items(sell Philosopher's Stone if you need to for Madred's*) untill the last item, here you need to look at what you are facing, it there are lots of ad, go for Frozen Mallet if there are lots of anoying ap, go for Banshee's Vale.

your shrooms wont do much damage but they will slow your enemy and they are nice wards. the key places to put them after lanening fase is baron, dragon and both red buffs and blue buffs. your shrooms are also great at farming, it will clean a whole creep push with one shroom and some darts.

at team fights you go in last and start puting blinding dart at ad-carry and start killing their mages, you will be targeted so you need you be agile and quick to get out and then back it you can.