What i want to do is make a title like Terraria just the rocking back and forth side of it not the graphics side i know that its just a .png rocking back and forth but could anyone help me and other people who read this and what to know how to do it?

So what i would like is to learn how to make a rocking back and forth image like the title displayed in Terraria?

Something like this for the people who don't know what Terraria is.

<http://www.youtube.com/watch?v=3K8PMG42l3M>