The children’s book team of Jim and Kate McMullan of Sag Harbor has branched out with a pilot for an Amazon Original Series that can be seen for free at the website of the retailer turned budding network. Episode one of “The Stinky & Dirty Show,” based on the McMullans’ “I Stink” and “I’m Dirty” books, is a 12-minute excursion into a Utah-like desert landscape a la Chuck Jones’s immortal Road Runner and Coyote cartoons for Warner Brothers, where, as then, towering rock formations figure in the plot.