Rek'sai Teemo Synergy.

Apparently it's a thing. Obviously shrooming an ally Rek'sai's tunnels has its benefits. Any enemy wanting some free gold will be finding their feet exploding with poison. There's one thing I've found more tempting to put yourself out of position to kill then a pink ward, and those are reksai tunnel's.

But placing shrooms on an enemy Rek'sai's tunnel is just as beneficial. They will get poisoned trying to engage on a gank and thus reveal themselves. Or they will be half dead as they try to go into a tunnel to escape. Eitherway, if I see anyone picking Reksai , I will always grab Teemo no matter which lane I'm in. This is easiest done in draft and ranked modes, but just in general too it can be very rewarding. These two champs have a very good set of complimenting attributes I think.