Hi this is my first guide. This is how i build Cho'Gath when i solo top. This not a FULL TANK guide but a beefy ap guide.

Cho'Gath was one of the first champions I tried but I didn't really use it since I discovered he could do some heavy damage when you build him with ability power.

For all who play Cho'Gath as a tank this guide is not for you.

Those are the runes I use but you can replace atk speed runes by magic penetration runes and replace regen runes by flat stats runes but I highly recommend keeping those cooldown reduction per lvl runes so you can use your ult more often and stack it to the maximum faster.

For my sumonner spells:

I use ignite for a good finisher when the jungler or another teammate comes ganking. It can also be usefull if your facing an enemy with healing abilities.

Ghost is good for chasing an oppenent or escaping ganking foes. I suggest keeping this ability.

You can replace ignite by Heal or Cleanse and Ghost by Flash but i prefer ghost.

Do not use Clarity or Clairvoyance, you do not need the mana restoration if you use my runes and masteries.

I use a 1-21-8 mastery set so i can have a high survivability as well as a good regenaration of both hp and mana and lots of cooldown reduction( that scales with lvl because too much cd reduction at start makes you go out of mana faster). You can always go more like an ap caster and replace the utility masteries by ability power ones in offense but you might go out of mana faster.

At start, you buy Doran's Ring or Dorans'Shield. I prefer the ring because your passive let you regenerate your health really fast. You try to go back when you can buy your Mercury's Treads and if possible Giant's Belt. You next item is Rylai's Crystal Scepter (makes your normal attack slow enemies movement speed if your Vorpal Spikes are on). After that, the order doesnt really matter, it depends on your enemie's team composition. If they are more AP try getting Abyssal Scepter and Guardian Angel fast and then Force of Nature. If they are more AD, get Thornmail, Zhonya's Hourglass and Guardian Angel. At last you can buy Zhonya's Hourglass\Abyssal Scepter or a Rabadon's Deathcap.

Cho'Gath is like a farming machine. With my build, you max out vorpal spikes first and you kill minnions so fast your oppenent cant do anything. His passive combined to Vorpal Spikes makes it hard for an oppenent to face him because for every minions he kills, he restore an amount of hp and mana. Usually people max vorpal spikes last because its not realy usefull against enemychampions when you dont have much hp but my guide is all about farming and vorpal spikes is the best ability for farming. You get at least 150 minion kills before the laning phase is over.

The order you level up you abilities is really important. Max out your Vorpal Spikes first is important if you want to farm properly. After that you level Rupture or Feral Scream as you wish. I personally prefer Rupture because it has more range but some people likes the silence effect. Like every other champions you level up your your ult when you can.

Cho'Gath is a really good champion in team fight because he has a mass silence and slow, a mass knocked airborne and a heavy nuke ultimate. This champion works well with almost every champion because he can play many roles, he does good damage and can tank pretty well and have a high base hp without the need of buying hp items.

In team fight, I suggest you initiate if there is no other better initiators (Malphite, Rammus, Shen, Galio, Leona or Amumu) and use feral scream first as it prevent enemie's champ for casting CC or nuke your carries down. You follow immediatly by Rupture as your enemies will try to focus down your allies. When you think you can kill it you use your ultimate on a squishee enemy and if well calculated you will kill him.