FANDOM


Treehouse of Horror XX
Directors
Mike B. Anderson
Matthew Schofield
Writer
Daniel Chun
Series
The Simpsons
Season
21
No. in season
4
No. in series
445
Original airday
Sunday
Original airdate
18th October 2009
Previous episode
Next episode

Treehouse of Horror XX is the fourth episode of the twenty-first season of The Simpsons.

The Simpsons
Season 1 | 1989–1990
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Season 2 | 1990–1991
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Season 3 | 1991–1992
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Season 4 | 1992–1993
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Season 5 | 1993–1994
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Season 6 | 1994–1995
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Season 7 | 1995–1996
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Season 8 | 1996–1997
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Season 9 | 1997–1998
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Season 10 | 1998–1999
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Season 11 | 1999–2000
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Season 12 | 2000–2001
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Season 13 | 2001–2002
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Season 14 | 2002–2003
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Season 15 | 2003–2004
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Season 16 | 2004–2005
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Season 17 | 2005–2006
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Season 18 | 2006–2007
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Season 19 | 2007–2008
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Season 20 | 2008–2009
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Season 21 | 2009–2010
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The Simpsons episodes
Season 22 | 2010–2011

•••1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22

Season 23 | 2011–2012

•••1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22

Season 24 | 2012–2013

•••1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22

Season 25 | 2013–2014

•••1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22

Season 26 | 2014–2015

•••1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22

Season 27 | 2015–2016

•••1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22

Season 28 | 2016–2017

•••1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22

Season 29 | 2017–2018

•••1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19