I've been thinking about making a paper version of this classical automata.

Link to the YouTube video

In the original version, mercury flowed inside a steel tube to change the centre of gravity of the acrobat making him tumble down the steps.

In my version I'm using paper tubes and coins. 

The weight of the coins rolling in the long central tube helps move the acrobat.

I've made a start, experimenting with the joints to make them as free as possible and finding a way to limit their arc of rotation. At the moment I have settled on pegs in holes for the joint. The triangular section on the upper surface of the 'leg' works as a movement stop, restricting the rotation to ninety degrees. Looking at the video I suspect that there is a connection between the arms and legs, I'm not sure as it is hard to follow the video but if necessary I'll use paper straps to link them together.