|“||“Mother, keep digging graves. Better do two. This isn’t going well.”||”|
After safely returning to Earth, Cody tells the head of U.S. security about Retik’s plot to invade Earth. Meanwhile, Retik's minions need money to buy a new truck to house the super ray gun, so Retik tells them to kidnap Cody and hold him for ransom. Unable to get Cody, they kidnap his assistant Jean. The henchmen take off with her in an airplane and bail out, jamming the controls. Cody comes to the rescue in his rocket suit, and successfully rescues Jean. Retik reprimands his underling Krog for failing to carry out his mission. Krog orders his men to pull a payroll heist, which succeeds in raising the needed cash.
- Clayton Moore (better known as TV's Lone Ranger) plays the villainous turncoat Graber.
A young boy named Johnny (Gregory Moffett), who is fascinated with outer space, is on a picnic with his widowed mother (Selena Royle, as Selena Royale), older sister (Claudia Barrett), and younger sister (Pamela Paulson) when he meets a pair of archeologists (John Mylong and George Nader) exploring a nearby cave. Later, as the family sleeps, he has a dream — that the Earth has been attacked by an alien named Ro-Man, using the "calcinator death ray", and that he and his family and scientist (Nader) are the only survivors. They try to elude capture by Ro-Man (played by actor George Barrows in a gorilla suit with a space helmet that looks a lot like a diving helmet), who turns out to have some very human failings despite his computerized mentality. Several members of the family are killed, but Ro-Man is destroyed by his controllers when he decides he'd rather experience human emotions. 
- The film's composer Elmer Bernstein was a fairly well known film composer who created memorable scores for such films like The Ten Commandments, The Magnificent Seven, and arguably his most famous; The Great Escape. Apparently the reason he scored such a Z-Grade film as Robot Monster was due to him being black listed from Hollywood by 'The House of Un-American Activities Committee' after being accused of writing reviews for a Communist newspaper.
- According to the Medved brothers' book "The Golden Turkey Awards", director Phil Tucker attempted suicide after the release of this film due to the overwhelmingly negative critical reaction it received. He put a gun next to his head and pulled the trigger. He missed.
- It was reportedly shot in just four days, utilized no sets, and was entirely filmed outside.
- The scenes on the view screen presented by Ro-Man come from a variety of sources: among them, the shots of New York in apocalyptic ruins are matte paintings by Irving Block from Captive Women (RKO, 1952); the shots of the headquarters of the Great Guidance (a rocket ship in launching position) was originally created for Rocketship X-M (1950, directed by Robert L. Lippert), also painted by Block.
- The film was not entirely filmed at Bronson Canyon. The scenes at the ruins of the home were shot in a residential hill area elsewhere.
- Originally released in 3-D.
- Is considered to be the first science-fiction film with stereophonic sound.
- After the lightning flash we see dinosaurs battling, and the footage comes from other films. The large lizards are from One Million B.C. (1940) (Hal Roach, 1940), supervised by Roy Seawright; the one brief shot of two stop-motion triceratops fighting is from Lippert Pictures' Lost Continent (1951), animator unknown.
- The original screenplay was written by Wyott Ordung.
- Close examination of the Ro-Man's helmet reveal it to be very similar to the helmets worn by the moon-men on the lunar surface in Republic Pictures' serial Radar Men from the Moon (1952).
Segment Two: Joel and the Bots point out the physics conundrums of Commando Cody. Joel mentions the bizarre physics of bumblebees and flight and the poor robots blow up.
Segment Three: Joel is afraid of Ro-Tom.
Segment Four: Joel discusses surrealism with the Bots.
- The Bots are present during the invention exchange for the first time.
- Joel and the bots discussing surrealism in segment four was used previously in Humanoid Woman.
- During the short, Josh Weinstein sneezes loudly while in the theater and (inadvertently or on purpose) jerks the puppet. The cast treat it as though it was Servo who sneezed and keep going, with Crow telling him 'gesundheit' and Joel patting him on the shoulder and giving a confused "You're not supposed to do that."
- Josh Weinstein did not like the idea of Robot Monster being riffed because he felt the film was too well-known, and already so ridiculous on its own that riffing wouldn't add much.
- First and only time the show used green coloring on the Shadowrama. In a 2014 interview, Joel Hodgson stated this was due to Comedy Central thinking that people would not see him and the Bots in the theater against a black and white film.
- Joel's claim in Segment Two about scientists being unable to explain how bumblebees can fly has been widely debunked. Science does have an explanation.
- "George Nader? That's Ralph Nader's naughty brother. He wrote "Safe at Any Speed." - Joel says during the credits for Robot Monster
Ralph Nader is an American political activist, most notably outspoken about automobile safety. In 1965, he wrote Unsafe At Any Speed. George Nader, while the star of this film, was not related to Ralph nor did he write a book called Safe At Any Speed.
- "Selena Royale? What a great movie! Wasn't Woody Allen in that?" -Joel says during the credits for Robot Monster
Joel is referring to the 1967 version of Casino Royale, a James Bond spoof that featured a young Woody Allen as Bond's nephew and head of SMERSH.
- "Lookin' through the knothole in Grandma's wooden leg."-Sung by Joel whenever we see Ro-Man lumbering around on the hillside.
From an old children's folk song. "Looking through the knothole in Grandma's wooden leg/ Who'll wind the clock up when I'm gone/ Go get the axe, there's a flea in Susie's ear/ And a boy's best friend is his mother."
- "It's Miller Day!"-Says Crow T. Robot upon a close-up shot of a wristwatch wearing actor soldering electronic circuits.
This is a reference to the Miller Genuine Draft "It's Miller Time!" ad campaign of the 1980's.
- "We'll be right back after this message from Geritol."
Crow is imitating Lawrence Welk, who hosted a variety TV show. Welk typically had a bubble machine on stage behind him. Geritol, a brand of vitamins for the elderly (the show's primary demographic), was his main sponsor.
- "But the hills are alive with...weird music." -Crow, as Ro-Man hikes through rough terrain as a strange soundtrack plays
Refers to the title song from The Sound of Music, a Broadway musical and film.
- "Armageddon married in the mornin'." -Tom during the marriage scene in reply to Joel's comment that it's an "Armaggedon weddin'."
This is a reference to the song "Get Me to the Church On Time" from My Fair Lady, a Broadway musical, which contains the line "I'm gettin' married in the mornin', Ding dong, the bells are gonna chime!"
- "One-punch Larry." -Crow nicknames Roy this after he is hit by Ro-Man.
One-Punch Larry was a nickname of Larry Lowenstein, a publicist and agent. According to his autobiography, he gained the nickname after scaring off a bigger kid by punching him once while defending a smaller boy.
- "I got the girl! I got the girl! Oh happy day! I will love her and pet her and hug her and squeeze her and I will call her Georgette." -Tom Servo as Ro-Man walks away with the captured Alice after fighting Roy.
This is a reference inside a reference. The line is based on one by Hugo, the Abominable Snowman, a character from a Bugs Bunny and Daffy Duck cartoon, who said: "My own little bunny rabbit! I will name him George, and I will hug him, and pet him, and squeeze him," after catching Daffy. Hugo was a reference to Lennie, from Of Mice and Men by John Steinbeck, whose guardian was named George. The MST3K crew would make similar references numerous times throughout their career.
- "Gomez, I'm not your new best friend."
According to J. Elvis Weinstein, this is an inside joke between him and Joel Hodgson about something they witnessed during their days as comedians in Minneapolis, MN.
- Ro-Man Leader: Earth Ro-Man, you violate the law of plan. Fact: you have captured the girl and not destroyed her. Fact:...
- Tom Servo: Fact.
- Ro-Man Leader: ...You have delayed the acceptance of the surrender of the others. This verges on failure.
- Ro-Man XJ2: There is one thing you do not understand, Great Guidance.
- Ro-Man Leader: You reject the plan?
- Ro-Man XJ2: I wish to make an estimate of my own.
- Ro-Man Leader: To think for yourself is to be like the Hu-Man.
- Tom Servo: Me-Man?
- Ro-Man XJ2: Yes! To be like the Hu-Man; to laugh, feel, want, why are these things not in the plan?
- Crow: (as the Ro-Man leader starts destroying Earth) Uh, cue the "Deus Es Machina".
- Joel: "Deus Es Machinena", isn't it?
- Crow: You say "Machinena", I say "Machina".
- Joel: Let's call the whole thing off.
- Tom Servo: (simultaneous) Let's call the whole line off.
- Released on DVD by Shout! Factory in November 2010 on Vol. XIX with Bride of the Monster, Devil Doll and Devil Fish.
- DVD special features include an introduction by J. Elvis Weinstein, "Larry Blamire Geeks Out" featurette, and the original theatrical trailer.
- Digitally available through Shoutfactorytv.com, Amazon Instant Video, iTunes, and VHX.
|preceded by: Season 0||MST3K Season 1||followed by: Season 2|
|1989 - 1990|
|101||The Crawling Eye||1989-11-28||106||The Crawling Hand||1989-12-26||111||Moon Zero Two||1990-01-30|
|102||The Robot vs the Aztec Mummy||1989-12-05||107||Robot Monster||1990-01-02||112||Untamed Youth||1990-02-06|
|103||The Mad Monster||1989-12-12||108||The Slime People||1990-01-09||113||The Black Scorpion||1990-02-13|
|104||Women of the Prehistoric Planet||1990-02-20||109||Project Moon Base||1990-01-16|
|105||The Corpse Vanishes||1989-12-19||110||Robot Holocaust||1990-01-23|