I believe that's called Papercraft but I'm not sure of a particular site that gives templates. I'm pretty sure if you searched for Papercraft templates on Google you would probably find something.

I can't remember the name of a website I played with a few years ago where you would get a 3d template of a small, blocky character which you would draw on with stencils, and then you could print it out and fold it into a 3d paper figure. I believe it was quite popular at the time, this was about 5 years ago.

[TOMT][website] Custom paper characters