Starting items are fluid when it comes to Teemo; With Toxic Shot (E) giving him 50 on-hit damage at level 9, Teemo has the pick of the litter. However, starting items are matchup dependent, so it’s important for you to both play to your strengths and counter the enemy laner.
Tier 1: Doran’s Shield and Doran’s Ring
In general, Doran’s Ring and Doran’s Shield are Teemo’s best starting items. For decent matchups that don’t involve a receiving ton of poke, I suggest grabbing yourself a Doran’s Ring. However, if you’re laning against champions that are poke heavy, I highly recommend taking Doran’s Shield as it will allow you to stay in lane for longer periods of time and eventually poke out the enemy laner. It’s important to take into account the trading patterns of the enemy laner when choosing your starting item. For champions that rely less on poking Teemo down and more on all-ins, Doran’s Ring is your best bet; not only will you have the health pool for the all-in, but it also allows you to effectively poke them out. However, for sustaining from poke, Doran’s Shield would be your best choice.
For the brutal Pantheon matchup consider starting Doran’s Ring and maxing Blinding Dart (Q); Teemo’s Blind Dart outranges Pantheon’s Spear Shot (Q). For a more in-depth breakdown of the matchup, watch IcyPhoenix’s video analysis.
Tier 2: Cull
If you’re feeling frisky, then consider taking Cull; it’s extremely gold efficient and gives decent laning stats to help you last-hit effectively. Only opt into taking Cull for matchups where you would take Doran’s Ring. You never want to take Cull into punishing matchups where Doran’s Shield is needed; a Cull start is about safely getting away greed, not getting away with feed.
Tier 3: Null-Magic Mantle and Boots
In very specific matchups it’s sometimes beneficial to start with Null-Magic Mantle or Boots. You can be greedy and start Null-Magic Mantle if you intend on rushing Wit’s End against an AP laner that doesn’t poke you whatsoever (Nautilus, Maokai, Singed etc.) Starting Boots can also be an option versus Darius if you need to avoid getting pulled in, but it isn’t optimal.