Do you want more free skins? Of course you do! Riot is giving away the Dreadknight Garen skin and all you have to do is follow one of their accounts. You will get a code which you can redeem in the shop in-game. This one is Twitter promotion. So, if you have a Twitter account (or make one just for this promo), head over here and Spin to Win!
As with the other skins you will get the champion for free if you don’t have Garen yet. I have no idea until this promotion runs, but I don’t think they’ll stop this one soon, since the Unchained Alistar and Riot Girl Tristana promotions are still running also.
[Update: 9-4-2014] You asked for it, so I looked it up. I found the skin for free for all the other regions as well. Click on your region to claim your free Dreadknight Garen! Don’t forget to share this post with your friends so everyone can enjoy their free Garen champion and skin.