Grasp of the Undying:
periodical healing makes augments Teemos poke and trading abilities with the added sustain.

Overgrowth:
In combination with Grasp of the Undying gives Teemo permanent health bonuses making him even tankier.

Taste of Blood:
and Ravenous Hunter are what enables Temoo to come out on top in trades with their permanent scaling lifesteal that scales both with attack damage and ability power.

Lethal’s Tempo:
periodical healing augments Teemo’s poke and trading abilities with the added sustain when dealing and receiving damage. Whenever you are hit or are dealing damage, this rune deals flat % max health and heals for a flat of % max health.

Legend: Alacrity:
Gives On-hit Teemo the needed attack speed boost with every takedown, making him an even bigger menace to trade against.

Coup de Grace:
Shrinking the enemies health bar comes with rewards, and On-hit Teemo will deal more damage to his targets once they are low, forcing them to back out of the lane or play passive.

Overheal:
With this build focusing on sustain and self-healing this rune takes full advantage of the item build providing a shield derived from the healing when at full health.

Ravenous Hunter:
To boost the self healing potential to the max, Ravenous Hunter awards permanent healing from ability damage for each unique takedown.

Taste of Blood:
To round it of Taste of Blood provides permanent passive healing from damage dealt to enemy champions.

Glacial Augment:
This rune is at the center of the build. It applies a slow to your auto attacks that increases over time and additionally your Twin Shadows and other active items with slow effects are augmented and now create a path of slow around each champion hit with that active item!

Time Warp Tonic:
Is here to help you catch your enemies or run away from them, using a potion or biscuit (from the rune Biscuit Deliver) gives you a movement speed burst.

Biscuit Delivery:
This rune will help you reach your later game potential. As you start of your match and build up your items, every tiny drop off sustain will come in very handy!

Dark Harvest:
Is the cornerstone of this build. Killing and participating in the execution of your enemies grants you their souls which in turn make it so you deal more damage for each soul you have gathered. Really dark!

Cheap Shot:
Grants you bonus damage towards slowed or immobilised enemies, paired with the slowing effect of your shrooms is deadly!

Ravenous Hunter:
Makes it so that your takedowns heal you for a % of health pool and the more takedowns you have the stronger the healing.