Best Christmas Pageant Ever: What did the Herdmans want to do to Herod?
In chapters 4 and 5 of The Best Christmas Pageant Ever there are actually multiple ideas mentioned about what the Herdman children want to do to King Herod after they learn that he intended to harm the baby Jesus. The Herdmans had never heard the story of Jesus's birth before, and when it is read aloud to them by the narrator's mother, they are shocked and angry to learn that Herod would want to hurt a baby. Imogene Herdman's initial reaction on page 47 is to exclaim, "My God! He just got born and already they're out to kill him!"
According to the narrator at the bottom of page 47, the Herdmans "all got mad" when they learned Herod is not a character present in the Christmas pageant because they "wanted somebody to be Herod so they could beat him up". This is not stated directly by a Herdman kid in this chapter, but it is what the narrator reports to us that they wanted. Furthermore she says that they "wanted a bloody end to Herod".
Later on page 50 when Mother is describing the evening to Father back at home, Father remarks to her, "According to you, their chief instinct was to burn Herod alive." She corrects him, however, and explains that their chief instinct was to save Mary and the baby Jesus, and that to want to "do away with Herod" was the correct instinct a person ought to have since it is correct to recognize that Herod is the villain of the story. Again, we do not see any Herdmans actually mention "burning alive", but we do get the impression that in any case they want to get revenge on Herod on behalf of the baby.
On page 52 after the Herdmans have gone to the public library to read about Herod and find out whatever became of him, they return to pageant rehearsal and report that Herod had in fact killed many people and lived to an old age. The narrator tells us, "The Herdmans wanted to rewrite the whole pageant and hang Herod for a finish. They couldn't stand it that he died in bed of old age."
All in all, it is clear that the Herdmans want justice for the persecuted baby and believe that revenge is the best way to achieve it. Whether they want to beat up, burn alive, or hang Herod, the bottom line is that they want him to suffer dire consequences for trying to orchestrate harm to happen to baby Jesus.