Piers Plowman is an allegorical poem by William Langland and except for this one the other three exemplifies the famous epics worldwide where "The Odyssey" is a classical (Greek) epic poem by Homer, "Paradise Lost" is a seventeenth-century epic poem by John Milton and "The Aeneid" is a Latin epic poem by Virgil. The epic poems illustrate a long narrative poem with a vast setting, superhuman characters, supernatural elements, etc. to tell the heroic tales or impart a moral lesson(as Milton to justify the way of Gods) which are culturally significant. Thus, except for the last one all three are epic poems.
A complication that makes it difficult for the characters to reach their goal in the story of the monkey’s paw is that the monkey’s paw they use grants their wishes, but it comes at a terrible cost.