Question: Undead Nightmare is a zombie horror-themed addition to what Western action adventure video game?

Context paragraphs:
List of Grand Theft Auto III characters: "Grand Theft Auto III" is an open world action adventure video game, released on 21 October 2001 for PlayStation 2.  It is part of the "Grand Theft Auto" video game franchise, developed by Rockstar Games and is the first installment in the third generation of the series.  As with future installments, "Grand Theft Auto III" features several major, supporting and minor characters.

Undead Nightmare: Undead Nightmare is an expansion pack to the 2010 video game "Red Dead Redemption".  As a standalone episode, it adds a zombie horror-themed single-player campaign, two multiplayer modes, and cosmetic additions to the environments and characters of the open world Western action-adventure game.  The alternate timeline story follows the returning protagonist and former outlaw John Marston as he seeks to find the cause and cure for a zombie plague that has infected his wife and son.  Marston liberates towns overrun by the undead and assists other non-playable characters with quests along the way.

Rolan's Curse: Rolan's Curse, known in Japan as Velious Roland no Majuu (ベリオス ローランの魔獣 ) is an action adventure video game developed by Sammy and released for the Game Boy in 1990.  Sammy released a follow up to "Rolan's Curse" for the Game Boy in 1992, entitled "Rolan's Curse II".

Asterix &amp; Obelix XXL: Asterix & Obelix XXL is an action adventure video game released between 2003 and 2004.  It is based on the French comic book series "Asterix", about the Gaulish warrior Asterix in the year 50 BC, as he and his best friend Obelix, battle the Romans.  XXL is actually an initialism for "extra extra large", meaning the game has a great number of additional features.  It was released in the United States (for PlayStation 2 only) with the title Asterix & Obelix: Kick Buttix.

Ross Hagen: Ross Hagen (May 21, 1938 – May 7, 2011) was an American voice actor, actor, director, screenwriter and producer whose television acting credits included "Daktari".  His film credits included "The Hellcats" in 1967 and "The Sidehackers" in 1969.  His video game credits included "Red Dead Redemption" and its expansion pack "Undead Nightmare".

List of Grand Theft Auto: San Andreas characters: "" is an open world action adventure video game that was first released in 2004.  "San Andreas" is part of the "Grand Theft Auto" video game franchise, developed by Rockstar Games and is the fourth installment in the third generation of the series.  As with previous installments, "San Andreas" features several major, supporting and minor characters.  Many high-profile celebrities have voiced these characters in the game including crime film veterans, Samuel L. Jackson, James Woods, Frank Vincent and Peter Fonda and prominent west coast rappers, MC Eiht, Ice-T, Frost and The Game.

Medieval Moves: Deadmund's Quest: Medieval Moves: Deadmund's Quest (Medieval Moves in Europe) is a 2011 action adventure video game developed by San Diego Studio and Zindagi Games and published by Sony Computer Entertainment on November 15, 2011 in North America and November 18, 2011 in Europe for PlayStation 3, which utilizes PlayStation Move.  It was officially announced at Electronic Entertainment Expo 2011 on June 5, 2011.  The game is from the same team responsible for "Sports Champions".

Animaniacs: The Great Edgar Hunt: Animaniacs: The Great Edgar Hunt is an action adventure video game released in 2005.  It was released in North America, Europe and Australia.  It is based on the animated cartoon series "Animaniacs" from Warner Bros. and features the same voice actors for the main characters.  The game is one of multiple "Animaniacs" video games.  It was the first Animaniacs-related project to be released since "Wakko's Wish" in 1999.  The game was released on the GameCube and Xbox.  A PlayStation 2 version was also released, but only in Europe.

Adventure Time: Finn &amp; Jake Investigations: Adventure Time: Finn & Jake Investigations is a 2015 action adventure video game developed by Vicious Cycle Software under license from Cartoon Network Interactive.  It was published by Little Orbit for Microsoft Windows, PlayStation 3, PlayStation 4, Xbox 360, Xbox One, Wii U, and Nintendo 3DS.  This is the fourth game based on the animated television series "Adventure Time" following "", and the first action adventure title in the series presented in full 3D graphics.  The game was first announced on April 21, 2015, and released on October 20, 2015 in North America, and was released on November 6, 2015 in Europe.

Red Dead Redemption: Red Dead Redemption is a Western action-adventure video game developed by Rockstar San Diego and published by Rockstar Games.  It was released for PlayStation 3 and Xbox 360 consoles in May 2010.  It is the second title in the "Red Dead" franchise, after 2004's "Red Dead Revolver".  The game, set during the decline of the American Frontier in the year 1911, follows John Marston, a former outlaw whose wife and son are taken hostage by the government in ransom for his services as a hired gun.  Having no other choice, Marston sets out to bring the three members of his former gang to justice.

Supporting paragraphs: Undead Nightmare Red Dead Redemption
Answer: Red Dead Redemption