I've captured a few stills from my video below to explain what I am doing - I'm not confident enough to speak on my videos yet ... I'm working up to that, you can just enjoy the birdsong and not have to listen to me droning on.
A crocodile stitch is created over two rows, a row of triangles (created by DC, CH, DC in a single chain space) and then the second row creates the crocodile scales by working into these triangles. The image below shows the triangles row. To get to the overlapping scales look you skip one triangle and work into the next.
The stitches are worked around the posts of the DC stitches of the triangle. Each half of the scale is 6 DC stitches.
Once the 6 DC are worked, then you need to work 6 more DC round the second DC of the triangle.
When you have done the second 6 DC you have created your crocodile stitch scale - ta da!
And here it is as a video, you get a great view of my chubby hands .... enjoy (I don't think Stephen Spielberg has anything to worry about)
This is how far I have got with my shawl so far ... I think another 10 or so rows should do it once I have spun up enough yarn.