I would actually roll sausages of fondant and attach them to the cake first in waves to give you the pattern and then cover with your final layer.
that's what it looks like to me also. looks challenging also. my question...how do you attach the sausages?
They should stick to the buttercream well enough, or if it's a crusting one you could always spray it with a little water (only a little!) to help the fondant stick to the crusted layer Then leave it to set up a little before you try covering it.
Thanks for the help!
Maybe use modeling chocolate snakes, so no one ends up eating thick rolled fondant.