Based on the ancient sculptures from the Hamangia Culture, around 5000 BC. https://en.wikipedia.org/wiki/Hamangia_culture

Update, September 12, 2017:
Because this piece got more popular, I'm uploading the blender file, so any of you can play with the dimensions in subdivision surface geometry if you'd like. Cycle the keyframes forward or back to toggle their orientation (upright to on backs). Enjoy! :)

Update, April 23, 2018:
I added a prop TV so they have something to watch. :-P

Yes

I know this slices properly in Repetier Host, but I can't guarantee success with the others.

I made two versions of each figure. I found they print best flat on their backs. However, if you want round backs you can print them in the default orientation. When they print on their backs, the arms and face have better surface quality, because I'm printing with a single extruder. Turn support material on. I set mine for about 28° overhang threshold. I used about 0.2mm layer height, and used textured spraypaint to fill in surface and smooth it out, but you can switch to a more fine resolution if you want.