This Build Guide for Chogath is for Jungle and is written by Malunoo, he is one of the best Cho Junglers in competitive play. His elo has topped out at 2500 and he plays for Team Curse.EU. Chogath is a very fast jungler and a phenomenal ganker.
Cho'Gath is pretty much a AoE Machine, all of his skills except his Feast (Ult - R) are AoE. In this guide we use him as a tanky champ, as he is naturally tanky so we will take advantage of that fact.
He has a strong clear time in jungle, strong ganks (if played well), and one of the best sustains in jungle. As a Tanky role your job is pretty much to initiate fights, as well as keeping them off of your Carries. Since 3 of your skills are AoE that makes it quite easy, with 2 of them being a type of CC (1 of those 2 being a hard CC - Rupture).
There is a place between dimensions, between worlds. To some it is known as the Outside, to others it is the Unknown. To those that truly know, however, it is called the Void. Despite its name, the Void is not an empty place, but rather the home of unspeakable things - horrors not meant for minds of men. Cho'Gath is a creature born of the Void, a thing whose true nature is so awful most will not speak its name. Its fellows have been poking at the walls that divide dimensions for a crack, a way into Runeterra, where they can visit their own personal paradise of horror upon the world. They are called the Voidborn, creatures so ancient and terrible that they have been removed from history altogether. It is rumored that the Voidborn command vast armies of unspeakable creatures on other worlds, that they were once driven from Runeterra by powerful magic lost to antiquity.
If such tales are true, then the rumors that follow must be equally true - that one day, the Voidborn will return. Even now, something dark stirs in Icathia, perverting the summoning rituals of the League to allow the presence of Cho'Gath. It is an alien creature of malice and violence, a thing that causes all but the most stalwart to cringe in fear. Cho'Gath even appears to feed on its predations, growing and swelling as it gorges itself. Worse yet, the creature is intelligent, perhaps greatly so, making most wonder how such a monster could be contained. Fortunately, the power of the League's summoning has confined Cho'Gath's presence exclusively to the League of Legends. It is here that summoners use Cho'Gath's Voidborn abilities to help decide the fate of Runeterra. The Terror of the Void knows what fate it would choose for Runeterra, given half the chance.
Woe betide the day when Cho'Gath grows weary of the League.