Roblox how to get 12th birthday hat. It was created for the 12th anniversary of roblox since its public release in september 2006 and was obtained by entering the promocodehappy12birthdayroblox. Hope you enjoyed watching the video. In this video i give you the instructions on how to get the 12th birthday cake hat in roblox as a part of the 12 year celebration of roblox starting back in 2006. As of january 28 2019.