Polaroids are great, but if you want to make your own weird version, Hackaday user Muth has a guide that links up a Raspberry Pi and camera to a thermal printer.
The project uses a Raspberry Pi Zero, camera module, TFT screen, battery, and few other switches and buttons. Everything gets crammed into a little box, then after the camera gets a button, you can instantly snap and print pictures.
They're low resolution and real weird looking, but that's all part of the appeal. Head over to Hackaday for everything you need to make one for yourself.