This episode marks the first appearance of Dr. Rockzo.
Song: Birthday Dethday
If you look carefully in the newspaper Pickles was reading after their concert, directly underneath the article about the Danish prince, you can see another article, titled, "Potato Gouging finally official, SENATOR STAMPINGSTON asked for all records."
Therefore, Senator Stampingston must be their state Senator.
During the montage about public reaction to Murderface's birthday, an anchorman states that "fires are raging in the South", yet in the footage that follows, a policeman can be seen wearing the flag of the city of Chicago on his sleeve.
In this episode, Nathan Explosion says Dr. Rockso is the finest rock and roll clown around, but in episode 17 "Dethclown", Nathan hates Dr. Rockso.
Senator Stampingston reveals that government polls show that half of the military are rabid Dethklok fans.
Jean Pierre, the band's sewn back together chef, makes an appearance during the birthday cake scene at Murderface's party.
Goat from the series' Megas XLR and Downtown, otherwise known as One-Eyed Fan in the premiere, returns for another cameo appearance. He can be seen briefly in the crowd during the demolition derby scene near the episode's end.
Dr. Gibbons: William Murderface's charts indicate a deep-seated rage, which is split off and repressed at its core. His self-loathing is expressed most publicly and unequivocally through bodily mutilation, tattooing, alcohol abuse and coprophilia. He blames others for his anger. He displaces his rage and its roots. He seeks punishment, castigation and ex-communication. This self-destruction is the only way to validate powerful voices he internalized as a child. This, combined with his immense wealth and popularity... should make for a monumentally horrific birthday.
Toki: (bringing the others' attention to what is being shown on the computer) Hey, look at this!
Nathan: Gah, e-vites. A birthday party for Murderface?
Skwisgaar: Where is it going to be? In a toilet? In a bus station?
Toki: Oh, that's brutal.
Skwisgaar: Can you believe, right off the top of my head, just making up like thats?
Pickles: Wait a minute! The guy's a nihilist, what does he want a birthday for?
Murderface E-vite: Inside, outside, up or down. Show up if you want, who gives a piss!
Nathan: Oh, f*** me! We're going to have to get him a gift!
Dr. Rockso: (sliding onto the stage with the microphone stand, wearing an open chested yellow tiger print jumpsuit, spiked wristbands, a painted clown face with a huge pink wig of hair and a motorcycle biker style cap and speaking in a falsetto voice) Ca-ca ca-ca. Yeaaaah! I'm Dr. Rockso, the Rock 'n' Roll Clown! I do cocaine! (standing and pointing to Murderface seated in the center of the stage in a long throne chair) Ca-ca-ca-ca, I hear it's somebody's birthday! I do cocaine! Dr. Rockso gonna make you a balloon face! (to Murderface with his back turned speaking normally revealing the back of his jumpsuit is open as well) Seriously dude, a lot of cocaine.
Skwisgaar: Hey Pickles, tell Murderface what you just told me about that guy...
Pickles: Oh, right...
Pickles: That dude you headbutted? The guy was a Danish prince! Can you believe that?
Skwisgaar: Pffft. The Dutch.
Pickles: Oh, check it out. He's got a brain contusion, a fractured skull, oh and he's last in line for the Danish royalty! That is messed up, dude.
Murderface: Well, that's what he gets for goin' after my hog.
Skwisgaar: Dude, I would have done the same thing. Dutch.
Pickles: Yeah well, it's official, I mean you're gettin'...really...good at headbuttin'.
Murderface: You mean I get to destroy American history? Literally?? (a single tear of blood falls from his eye)
(the band is discussing a gift for Murderface)
Nathan: (pointing to their advisor) ...and the birthday cake, it's gotta be totally metal! Got it?
Skwisgaar: Or maybe like we, get him an endangered species, and then we could kill it? That'd be cool. I just read about this thing online, you can buy a star and name it; like what if we named it like Muhammad Ali, the black prize fighter - that would be his gift... (his suggestions are met with blank expressions from the others) f*** you.
(Toki and Skwisgaar stand side by side, watching the crowd)
Skwisgaar: This is a complete and total, you know, sausage festival.
Toki: I love Sausage Festival.
Toki: Like in Vienna.
Skwisgaar: No, no, Toki that was a sausage festival.
Toki: Yeah, that was good.
Skwisgaar: Yeah, it was a Vienna porksaus - uh, no this means that there is no good-looking ladies to put you-know-what inside of them.
Toki: The sausage?
Murderface: I guess this is a good time to start my side-band, Planet Piss... (to the servant/executioner at his door) I shall send for the rest of my parcels in the morning. (gives the servant/executioner the middle finger).
Nathan Explosion: And now, the blackest present for the most brutal of all bass players...
(a spotlight highlights a giant black box with a red ribbon and bow as it descends from the ceiling; the top of the box is lifted as the box flaps fall down to reveal it is empty) NOTHING!
Skwisgaar Skwigelf: Anyways, what were you talking about a second ago, I'm sorry I cut you off.
Toki Wartooth: Oh, I gots to make something for Murderface. I'm gonna make him a macaroni murladie.
Skwisgaar Skwigelf: I'm sure he'll hate that.
On the season one DVD, this episode is listed as "Birthdayface"
This episode aired with a TV-MA rating.
The guys from the band Metallica returned to voice characters again for this episode. Kirk Hammett voiced the Queen of Denmark and James Hetfield was the Sniper.
This episode was available online at Adult Swim's Adult Fix two days before it premiered, under the alternate title Birthdayface.
Immediately after Nathan introduces Dr. Rockso, part of the audience is shown. The large guest in the tan suit bears striking resemblance to Peter Grant, the manager of bands such as Led Zeppelin, as well as a record executive for Swan Song Records. He can be recognized for his large size and signature beard and facial hair.
When Dr. Rockso the Rock 'n' Roll Clown announces he is going to make Murderface a balloon face, what he actually makes is a balloon replica of Bootsy Collins' famous signature star-shaped bass guitar called the "Space Bass". Bootsy Collins is a pioneering funk bassist, singer, and songwriter notorious for his involvement alongside George Clinton as part of the legendary funk rock group Parliament-Funkadelic (P-Funk) as well as his own work as a solo artist and in his own band called Bootsy's Rubber Band.
Toki: (describing Murderface's new car) ...big fat tires and everything!
This is an obscure reference to a line from the song "Highway Star" by the popular 1970's British hard rock band, Deep Purple.
Murderface's birthday gift is a car which was the Presidential limousine that John F. Kennedy was assassinated in. It has also now been souped up and "desecrated", as Nathan Explosion puts it, by having the driver's seat replaced with the theater chair which Abraham Lincoln sat in when he was assassinated.
The arcade game that Murderface plays near the beginning of the episode, Wheelchair Bound, bears a striking similarity to the arcade classic Paperboy. Wheelchair Bound has a controller shaped like wheelchair wheels, and the original Paperboy arcade games had replica bicycle handlebars that players used to control the paperboy.
Doctor Rockso, the Rock 'n' Roll Clown at Murderface's birthday party is wearing a skintight open-chested one-piece jumpsuit similar to those commonly worn by flamboyant 1980's "hair metal" frontmen such as David Lee Roth of Van Halen, Gene Simmons of KISS, or even Steven Tyler of Aerosmith.