Dragon Fire

[donec]

I am wanting to try and create a panel that goes on the front of my 2009 gs se5 below the frunk. I want it to look like fire in a dragons mouth. The problem is I remember as a kid they had these toys and cards and such that when you moved them the image changed. Now as chance would have it I received an advertisement card in the mail that is a card that has this feature. When you hold it one way it says 7 days/week and when you hold it another way it says 24 hours/day. There are other changes like day to night. I don't know what this process is called, but there is an image glued to the back of a piece of plastic that has ridges. Here is a couple of images of the card so you can see what I am talking about even though you can not see the change in the image.
7301773018 Now my question is does anyone here know what this process is called so I can research it? Any information would be appreciated.