Year One is a comedy movie which revolves around the charcters Zed and Oh (Jack Black and Michael Cera). After being banished from their homeland, Zed and Oh two neanderthals, embark on a journey through their ancient world. Along the way, they encounter Adam and Eve (Harold Ramis and Rhoda Griffis), Cain and Abel (David Cross and Paul Rudd), and Abraham (Hank Azaria).
In an interview regarding Be Kind Rewind, Black stated that Year One will be about two men running around in Moses' time. He said that the movie is similar to Monty Python's Life of Brian. Black stated that it might be fun to see all the stories of the Bible in a modern movie.
In an interview with MTV, Cera described it as a comedy set in Biblical times with Black's character Zed, looking for some kind of meaning for his life. Black warned viewers expecting a comedy along the lines of Ghostbusters or Knocked Up that the style of the film is much more along the lines of the Monty Python movies.