Many elements of Michael Shaw Fisher’s comedy The Amazing Sex Life of Rabbits remind one of other works that use the familiar trope of a childless couple, unable to conceive, going to extreme lengths to become parents. Here, the factors that decide the deal are typical of the darker riff on the Golden Rule—i.e., “Whoever has the gold, makes the rules.” In Fisher’s 75-minute show at the Fringe Encore Series, fanciful variations on the trope provide enough laughs to forget today’s economic disparities.