The art of parody is long established in the literary world, starting with the anonymous poet who imitated Homer’s epic style.
Usually having a mocking or satirical intent, the parody of a poem both brings new attention to the original on which it’s based, and establishes itself as a work in its own right. Who knows if anyone would remember The Old Man’s Comforts and How He Gained Them by Robert Southey, even though he was Poet Laureate for thirty years, if Lewis Carroll hadn’t included You Are Old, Father William in Alice’s Adventures in Wonderland?
satisfies the rules of parody by using another poem as a template in a way that’s immediately recognisable, but its message is not humorous,and gives it a darker, apocalyptic message.