My first build on mobafire, this is attack speed cho. It is a troll build, however, can prove highly successful as it does make sense. The key in this build is the fact that vorpal spikes scale with AP. Without having high AD, cho' gath can hit really hard with each attack due to the additional 20 magic damage to attacks, at level 1. At maxed level 5, they add 80 magic damage in addition to 30% of your ability power. Now this can easily add a total of 150 magic damage per attack. Now you may think this is not much, but remember that we are building attack speed cho' gath, not attack damage. Also, the beauty of this troll build is that you can play cho'gath as normal, with the AP provided by malady and nashors tooth. Further, cooldowns are essential to any effective cho'gath and these items help you spam out your rupture as much as you want.

Runes don't really have a game changing effect. Flat AP runes can be nice for the added punch in your skills, or cooldown reduction glyphs. If you are feeling a bit squishy, some nice defence runes such as armor or MR can help you out.

Again, don't really create a huge difference. Just ensure to pick up the free armor and magic pen. as these will help quite a bit. I like getting 9 in the defence tree for that added early game HP.

This is where its interesting. Your items will have teammates chuckling and opponents angry at getting beaten by an absolute troll. Cho' Gath is helped out by rushing a Rod of Ages, as it really suits him, giving extra tankiness along with nice AP. Don't get it. You want a malady as soon as you can. The AP it gives is nice and the attack speed is great. At this point, playing cho'gath can be done as usual, spamming ruptures and going in for Nom's when they get low. However, on ruptures, you can run in to autoattack and if the enemy is unwary, you will absolutely shred them. Also, the more the merrier as your vorpal spikes give you AOE auto attack damage. With attack speed Cho'Gath, you always have to be wary of where your spikes are pointing, they can make the difference between life and death. After you grab guardians angel, you should be a huge massive nom'tastic caster that can shred anything around you. Feel free to target tanks in a team fight and watch as they get torn apart.

Any attack speed items can work in this build, as long as you maintain a bit of AP. The high base damage of rupture keeps you effective against squishy champions, but that extra AP always helps.

Pros:

Ridiculous farming. The passive means easy regen. (More so than full AP cho'gath)
High team utility. Still providing that knock up and AOE silence, but also a fighter that can really get in there and punish the enemy team.
Gentleman Cho' Gath is the best skin in the game.

Cons:

Can be subject to abuse from teammates, until you ace the enemy team and win.
If your team comp is not decent, you will not be able to survive long enough, and a full AP or tank cho'gath would be much better. (decent as in not 4 ranged carries)

Really not too different from standard Cho' Gath builds. AP for your spells, AS for your spikes and GA for the survivability.

Oh, and of course an attack speed cho' gath is purely a troll. Prepare to embarass the hell out of your opponents when you stomp them with your malady.