If he has a positive K/D and more than 50 creep kills before 25minutes you're screwed.
First, carries: Master Yi, Twitch, Tryndamere, Shaco, Fiddlesticks, Evelyn.
Second, champs who are strong early game, and therefore will not be very useful late game unless they get some early kills: Pantheon, Ezreal, Jax
Third, special cases: Cho'Gath, because of feasts.
Anyone said Jax yet?
If farmed enough, he can demolish teams late game. You need to stunt his growth early on, as he is easily harassed.
Pantheon, especially past level 3.
Tryndamere, once he gets his Endless Rage, a competent Trynd would get away most of the time.
HEIMER. You shut down his farming, then you win.
Anyone who jungles. Specifically, Fiddlesticks and Warwick. One time I was soloing dragon as Fiddle, a Teemo came by and I got ganked. From that point on I was extremely underleveled.
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