Uncle Zombie and Mr. Zombie did not specify which one was a thousand-year-old zombie. In the novel Mr. Zombie, the main character, Zombie Shane, did not have a thousand years of lifespan. Before he died, a character called "Millennium Zombie" appeared, but this character was not described in detail, so we can't be sure if he really existed. In the novel " Zombie Uncle ", the main character, Uncle Morconson, was a zombie with a lifespan of a thousand years. He was an important character in the novel and had experienced many adventures and stories. However, due to the complexity of the plot, we can't be sure if there is a "Millennium Zombie" character in it.