The famous treehouse segment you are referring to is called "The Raven." It is a classic reading during a thunderstorm that appears in "Treehouse of Horror" episodes of "The Simpsons." In this segment, the Simpson family, usually Bart, reads a parody of Edgar Allan Poe's famous poem "The Raven." The poem is adapted to feature the characters of "The Simpsons," with Homer as the narrator and Lisa as the daughter being visited by the ominous raven. The segment often incorporates humor and references to the show, creating a unique and entertaining twist on the original poem.