Rune Build - Why

In the hybrid build, I take both ArP and M.Pen. I take it because I think it's the best way to be a hybrid overall. And if you want to go a little more AP, or a little more AD, you can, you have half of the runes for it!

In the AD build, I go ofcourse for the ArP for the little extra damage througout the game, IMO, ArP Is better than pure damage/damage per lvl runes.

In the AP build, it's the same reason but instead with AP on red marks. You can however go AP per lvl glyphs instead of M.res glyphs, but that M.res helps ALOT early game when you are the most squishy.

The HP per level seals are imo nearly essential for a Teemo! Teemo is one of the squishies champions ingame, and though flat armour seals helps alot early game, the hp runes makes up mid and late game.

The quints are different in each build.
AP build is flat M.pen quints for that extra DoT damage from E and the shrooms.
Hybrid build is as I mentioned earlier for extra damage both for the magic and the ad damage, and then another MS quint. I don't think that 3 is necessary, for the Move Quick and the Move Quick Activate makes up for the 2 other quints.
In the AD build, again only one MS quint, and instead of 3 ArP quints, the 1,5% MS is good for kiting with you blind, Frozen Mallet proc and your shrooms, if you ever get hit by them.