a pogo stick. Thanks to some quick thinking by Zoidberg, who uses the pogo stick to cut the wires to the Christmas lights, which then electrocutes Santa, the crew manage to force him back into the chimney, where an explosion sends him and his mechanical reindeer tumbling into the stratosphere. During Xmas dinner, Fry gives a toast on the importance of togetherness at Xmas. Everyone celebrates by singing "Santa Claus Is Gunning You Down". However, Santa vows to enact revenge on the crew next Xmas. Production The plot for this episode was one of the first storylines that Matt Groening and David X. Cohen came up with aside from the series' pilot. They had the basic idea before they pitched the show to Fox, although they did not develop the detailed plot until much later. The episode ended up being controversial although those involved with the show did not expect it to be. Fox was concerned that advertisers would find the episode too controversial for the time slot. When they made a second episode featuring Robot Santa it was delayed for nearly a year before being broadcast in a later time slot. John Goodman guest stars in this episode as Robot Santa; however, he was unavailable to reprise the role in the later episode "A Tale of Two Santas" so he was replaced by John DiMaggio. Conan O'Brien makes an appearance as his own head in a jar. In order to make a visual joke that O'Brien has a large head in real life the head was drawn sticking out the top of the jar. This choice caused many difficulties for the animators because it did not work with the animation layers typically used for other head-in-a-jar characters. Frank Welker voices Fry's parrot and created the annoying squawk used. The initial squawk he made was considered to be annoying but according to Cohen they had him continue to make the squawk more annoying until he had done nearly a hundred different parrot squawks. In this episode, Bender receives a card from the machine that built him, referring to him as "Son #1729", a reference to the Hardy–Ramanujan number. According to Ken Keeler, co-executive producer of the series, they could have chosen any number but chose to include an interesting one instead. Many of the maths and science jokes in the series found their way into Futurama in this way. Another