Question: Batman: Under the Red Hood starred an actor known for playing which character on How I Met Your Mother?

Context articles: Death of the Family
Red Hood
The Man Behind the Red Hood!
Red Hood and the Outlaws
Batman: The Killing Joke
Tokyo Red Hood
Batman: Under the Hood
Neil Patrick Harris
Robin War
Batman: Under the Red Hood

"Death of the Family" is a 23-issue comic book story arc first published by DC Comics in 2012 featuring the fictional superhero Batman and his family of supporting characters.
 The arc spans several titles featuring characters of the Batman family including: "Batman", "Batgirl", "Batman and Robin", "Catwoman", "Detective Comics", "Nightwing", "Red Hood and the Outlaws", "Suicide Squad", and "Teen Titans".
 The story involves the return of Batman's arch-enemy, the Joker, and his plan to destroy all of the people Batman has come to rely on over the years: the multiple Robins, Batgirl, Catwoman, Alfred Pennyworth, and Commissioner James Gordon.
 The title is a reference to the classic Batman story arc "" (1988), in which the Joker murders Jason Todd.
The Red Hood is an alias used by multiple fictional characters and a criminal organization appearing in American comic books published by DC Comics.
 Jason Todd is the most widely known version of the incarnation, and he assumes the Red Hood identity in the main DC Comics continuity.
"The Man Behind The Red Hood!"
 is a comic book story arc in the "Batman" and "Detective Comics" series.
 It features Batman and a few University students trying to crack a decade-old case.
 It features the earliest origin story for the Joker.
Red Hood and the Outlaws is a superhero comic book published by DC Comics.
 Commissioned in response to the growing popularity of the character of Jason Todd, a former protege of Batman who took a turn as a villain following his resurrection, the book depicts Jason's continued adventures as the Red Hood, on a quest to seek redemption for his past crimes, forming a small team with two of his fellow anti-heroes.
Batman: The Killing Joke is a 1988 DC Comics one-shot graphic novel featuring the characters Batman and the Joker written by Alan Moore and illustrated by Brian Bolland.
 "The Killing Joke" provides an origin story for the supervillain the Joker, loosely adapted from the 1951 story arc "The Man Behind the Red Hood!
".
 Taking place over two timelines, "The Killing Joke" depicts the Joker attempting to drive Jim Gordon insane and Batman's desperate attempt to stop him.
Tokyo Red Hood (東京赤ずきん , Tokyo Akazukin ) is a Japanese manga written and illustrated by Benkyo Tamaoki.
 Its serialization began in the monthly "Comic BIRZ" in 2003.
 The manga is popular for its young main character and the different sex acts she partakes in.
 It's also known for its over-the-top gore and violence.
"Batman: Under the Hood" (also known as "Batman: Under the Red Hood") is a comic book story arc published by DC Comics, written by Judd Winick and primarily illustrated by Doug Mahnke.
 Featuring Batman in the monthly title of the same name, it ran from November 2004 to June 2005, before going on a short hiatus and returning from November 2005 to March 2006.
Neil Patrick Harris (born June 15, 1973) is an American actor, comedian, magician, and singer, known primarily for his comedy roles on television and his dramatic and musical stage roles.
 On television, he is known for playing the title character on "Doogie Howser, M.D." (1989–1993), Barney Stinson on "How I Met Your Mother" (2005–2014, for which he was nominated for four Emmy Awards), and Count Olaf on "A Series of Unfortunate Events" (2017 onward).
"Robin War" is a comic book crossover storyline published by DC Comics.
 The event ran from December 2015 to January 2016 in the books "Robin War", "Grayson", "Detective Comics", "We Are Robin", "Robin, Son of Batman", "Gotham Academy", "Red Hood/Arsenal", and "Teen Titans".
Batman: Under the Red Hood is a 2010 American animated superhero direct-to-video film produced by Warner Bros.
 Animation and released by Warner Home Video.
 It is the eighth feature in the DC Universe Animated Original Movies series.
 It was released on July 27, 2010.
 The film stars Bruce Greenwood as Bruce Wayne/Batman, Jensen Ackles as the Red Hood/Jason Todd, John DiMaggio as the Joker, Neil Patrick Harris as Nightwing/Dick Grayson, Jason Isaacs as Ra's al Ghul, and Wade Williams as Black Mask.
 The screenplay was written by Judd Winick, who also wrote the "" run in the monthly "Batman" comic.As in the comic, it focuses on Batman dealing with the return of his former apprentice, the second Robin, Jason Todd , who now goes by the moniker of Red Hood, a murderous vigilante and the former alias of Batman's archenemy , The Joker , on whom Jason is trying to exact revenge.