Question: Which Victorian villain is parodied in the "Treehouse of Horror XX" episode of The Simpsons?

<P0-S0> "Treehouse of Horror XX" is the fourth episode of "The Simpsons"<nowiki>'</nowiki> twenty-first season. <P0-S1>  It first aired on the Fox network in the United States on October 18, 2009. <P0-S2>  This is the twentieth "Treehouse of Horror" installment, containing three self-contained stories: In "Dial "M" for Murder or Press "#" to Return to Main Menu", Lisa is forced into a Hitchcockian murder scheme by Bart; in "Don't Have a Cow, Mankind", Springfield is once again overrun by zombies thanks to Krusty Burger's latest sandwich; and in the "Sweeney Todd" parody, "There's No Business Like Moe Business", Moe the bartender bleeds Homer dry to create the perfect microbrewed beer. <P0-S3>  An estimated 8.59 million viewers tuned in to watch the episode. <SEP> <P1-S0> This is a list of "Treehouse of Horror" episodes produced by the animated television series "The Simpsons". <P1-S1>  "Treehouse of Horror" episodes have aired annually since the second season (1990) and each episode has three separate segments. <P1-S2>  These segments usually involve the family in some horror, science fiction, or supernatural setting and always take place outside the normal continuity of the show and are therefore considered to be non-canon. " <P1-S3> Treehouse of Horror" episode aired on October 25, 1990 and was inspired by EC Comics Horror tales. <P1-S4>  Before "Treehouse of Horror XI", which aired in 2000, every episode has aired in the week preceding or on October 31; "Treehouse of Horror II" and "Treehouse of Horror X" are the only episodes to air on Halloween. <P1-S5>  Between 2000 and 2011, due to Fox's contract with Major League Baseball's World Series, several episodes have originally aired in November; as of 2011 every "Treehouse of Horror" episode has aired during the month of October. <P1-S6>  From "Treehouse of Horror" to "Treehouse of Horror XIII", all three segments were written by different writers and in some cases there was a fourth writer that wrote the opening and wraparound segments. <P1-S7>  For "Treehouse of Horror", there were even three different directors for the episode. <P1-S8>  Starting with season fifteen's "Treehouse of Horror XIV", only one writer was credited as having written a "Treehouse of Horror" episode, and the trend has continued since. <SEP> <P2-S0> "Treehouse of Horror IX" is the fourth episode in the tenth season of the American animated television series "The Simpsons". <P2-S1>  It first aired on the Fox network in the United States on October 25, 1998. <P2-S2>  This is the ninth "Treehouse of Horror" episode, and, like the other "Treehouse of Horror" episodes, contains three self-contained segments: In "Hell Toupée", Homer gets a hair transplant and is possessed by the spirit of an executed criminal; in "Terror of Tiny Toon", Bart and Lisa are trapped in a special, extremely violent episode of "The Itchy & Scratchy Show"; and in "Starship Poopers", Marge reveals that Maggie is the product of a one-night stand with the alien Kang. <SEP> <P3-S0> Sweeney Todd is a fictional character who first appeared as the villain of the Victorian penny dreadful "The String of Pearls" (1846–47).