Claim: Christmas Flintstone, from The Flintstones' fifth season, was written by Warren Foster and directed by Joseph Barbera and William Hanna.
Evidence: "Christmas Flintstone" (also known as How The Flintstones Saved Christmas on VHS releases) is a Christmas episode from season 5 of the animated television series The Flintstones, which aired on ABC on December 25, 1964. Season 5
Episode 15 Joseph Barbera
William Hanna Warren Foster Warren Foster (October 24, 1904 – December 13, 1971) was an American writer, cartoonist and composer for the animation division of Warner Brothers and later with Hanna-Barbera. Joseph Roland Barbera (/bɑːrˈbɛərə, ˈbɑːrbərə/ bar-BAIR-ə, BAR-bər-ə, Italian: [barˈbɛːra; March 24, 1911 – December 18, 2006) was an American animator, director, producer, storyboard artist, and cartoon artist, whose film and television cartoon characters entertained millions of fans worldwide for much of the 20th century. William Denby Hanna (July 14, 1910 – March 22, 2001) was an American animator, director, producer, voice actor, cartoon artist, and musician whose film and television cartoon characters entertained millions of people for much of the 20th century.