Cho'Gath

Strengths

Try to line up your attacks with Vorpal Spikes so that they kill minions and harass enemy champions at the same time.
If you're having difficulty feasting upon champions, try eating minions until you're larger.
Using Rupture on creeps in combination with Carnivore is a good way to gain Health and Mana.

Passive · Carnivore — Whenever Cho'Gath kills a unit, he recovers Health and Mana. The values restored increase with Cho'Gath's level.
Q · Rupture — Ruptures the ground at target location, popping enemy units into the air, dealing damage and slowing them.
W · Feral Scream — Cho'Gath unleashes a terrible scream at enemies in a cone, dealing magic damage and Silencing enemies for a few seconds.
E · Vorpal Spikes — Cho'Gath's attacks release deadly spikes, dealing damage and slowing all enemy units in front of him.
Ultimate · Feast — Devours an enemy unit, dealing a high amount of true damage. If the target is killed, Cho'Gath grows, gaining maximum Health.

A suggested 5-lane lineup built around Cho'Gath, based on hero partnerships and role synergy — not win rate.