I recently played in a match with a riot squad 
and i wondered how I get it. It's not available in the shop and it's a really nice skin I would love to have. If it's one of those skins that require a code would someone be kind enough to give me a code?
It was one of the special 'Riot' skins from back in 2010. During events which Riot attended (PAX, Gamescom, MLG, etc.), they would give out codes for this skin. However, they also would sometimes open it up to players to purchase for RP during these events as well (since not everybody can be at the events where they distribute these). Riot Singed was shelved when they brought out K-9 Nasus. And since then we've had Riot Graves as well as Riot Blitzcrank.
At this point, getting a code for it is likely the only way you'd get it. I wouldn't rely on them putting it back in the store any time soon. However, the skin is so old now that I doubt there are any valid skin codes for it still laying around.
There's also a remote possibility that they're enabled for the mystery gift feature, though I haven't heard about the old Riot skins specifically in this regard. However, I did receive a legacy skin from the mystery gifting (Spectacular Sivir).
