[{quoted}](name=Zherron Vorse,realm=NA,application-id=cIfEodbz,discussion-id=1L8oYwfl,comment-id=0000,timestamp=2017-01-27T05:00:34.340+0000)
As a Teemo main I can tell you we are the most horrible breed of human. We enter games to not win or lose.. We enter to make as many people as mad as possible whether it is for us to feed like no-ones business and make our team mad, or to get super fed and leave shrooms that 1shot people on the enemy team and make them rage quit all while spamming our laugh and mastery emotes (which if you are a Teemo main needs to be level 7).
And Teemo loses to Yasuo with every build except for AP Burst Assassin Teemo. Which uses the build:

Combined with Thunderlords and Greenfather's Gift you wait for Yasuo to walk near your invisible cute self then you decloak and use the Hextech Gunblade Active while you are mid Q animation then 2 auto attacks and he'll be dead. The second auto attack is often not needed.
Unless it's a Tank Yasuo then you just lose unless you can trick him into multiple shrooms.
Good tips! Also
"if you are a Teemo main needs to be level 7."
I feel bad now! I need one more S to be mastery 7! D: