How to get this hat?

Hey all, relatively new to this game. I was looking through QR codes and found this. I thought it was really cool that the game has a hat so similar to Finn's hat. Is this a customized hat or is there an actual hat in the game? If so what is the name? Thanks!!

Hey all, relatively new to this game. I was looking through QR codes and found this. I thought it was really cool that the game has a hat so similar to Finn's hat. Is this a customized hat or is there an actual hat in the game? If so what is the name? Thanks!!