Is this a rainbow snake, Farancia erytrogramma?
Snake, as portrayed in tiles on the walls of the NYC uptown subway stop (A-B-C)
at 81st and Central Park West. (ISO, no zoom, no flash).
Image: GrrlScientist 2008. [wallpaper size].
I suspect this is a farancia erytrogramma or a rainbow snake though I think the artist took some liberties. The rainbow snake is a figure of myth in many cultures, so it's kind of a natural for artistic expression.