Films watched: X Marks The Spot and King DinosaurX Marks The Spot is notable for being the first short film featured on the show that was not an episode of a Film Serial such as The Phantom Creeps or Undersea Kingdom.
- Joel reads some poetry to the 'Bots, who sport beatnik beards.
- Joel's incredible invention is an incredibly stinky sweat sock; make of that what you will. Frank manages to flatten Dr. Forrester and has to scoop him up with a shovel, so he's the invention for them.
- Crow has a mild existential crisis on what's appropriate for him to do to judge others' driving habits, thanks to the short.
- Joey the Lemur gets his very own song and educational bit. Joel gets rather carried away in the role.
- Joel is The Emotional Scientist, but he doesn't want to do it. Crow fills in for all of ten seconds, but their turmoil over the event causes Joel to step back in.
- Since this is the fourth Robert Lippert film the crew have seen, Crow demands an explanation... just not with visual aids or song; he's not worth it. Joel compromises by demonstrating a theremin. The MSTies from Milwaukee wrote a letter and show off a scorecard they created. The Mads decide to go to a Kurosawa film festival.
The Mystery Science Theater 3000 presentation of King Dinosaur has examples of:
- Amusing Injuries: Dr. Forrester gets pancaked by an elevator.
- Anything but That!/Call-Back: Upon seeing the opening credit "Lippert Productions", Joel and the Bots dredge up memories of other Lippert films they've been forced to watch.
- Artistic License – Biology: That's not a lemur, it's a kinkajou. They're not even related to lemurs.
- Bee Afraid: "Relax?! There's a bee the size of a moose over there, and you want him to relax?!"
- Mighty Whitey: As usual, Joel and the 'bots pick up on The '50s-style arrogance, especially after the Nuke 'em ending.
- No Animals Were Harmed: Averted.Joel: You know, guys, lizards were hurt in the making of this film.
- The Scrappy: In-Universe example with Joel's puppet, "Joey The Lemur". Crow and Servo quickly get fed up with Joel's over-the-top obnoxious puppeteering. Fortunately, they don't take their frustrations out on the kinkajou which appears in the actual film.
- It also became one out of universe, to the point where the show itself spoofed it in Last of the Wild Horses. It doesn't help that Joel blows his lines several times; apparently this was the best take they got and everyone just wanted to move on.
- And even worse, Joey has not yet appeared in the film by the time the sketch happens, making it pretty darn confusing on first viewing. They try to cover it with Joel saying he read a film guide that says it'll happen. Of course, many fans have pointed out that the problem would have been resolved a lot more smoothly by simply flip-flopping the sketch with the following one, which doesn't relate to the film at all.
- And to top it off, there's no lemur in the film anyway. Joey is a kinkajou.
- Shout-Out: "I'm your boyfriend now!"
- Slurpasaur: Pointed out when Dick called the iguana a Tyrannosaurus rex.Dick: It resembles the Tyrannosaurus rex from Earth's prehistoric age.Servo: No, it doesn't.Crow: Sorry, no way.Dick: This monster dominates just as similar ones dominated Earth 125 million years ago. It's like living in the past.Crow: It's an iguana!(later when Ralph and Patricia encounter the lizard)Patricia: What is it?!Crow: It's an iguana, now shut up!
Servo: How did they get him to shake like that?Joel: They covered him with shag carpeting.Servo: Yeah. Poor elephants.
- Lampshaded again when the "mammoths" show up.
- Soundtrack Dissonance: During the climax, the bots note that the musical score seems to be mocking the on-screen action (what with the muted trumpets going "Nah nah nah NAAAH nah!" and all).
- Unusually Uninteresting Sight: One of the scientists laughs that there's nothing dangerous with the planet, and that there aren't any "race of super beings".Servo: (as scientist) All we've seen are giant mutated animals!
- Visual Pun:Dr. Forrester: Okay, look at me. Take a long gawk at the pocket scientist!
- Actually Pretty Funny: Crow approves of the visual pun.
- What the Hell, Hero?: Every time Dick pushes one of the girls down — which happens disturbingly often.
The Mystery Science Theater 3000 presentation of X Marks The Spot has examples of:
- Elmuh Fudd Syndwome: Commissioner Arthur W. McGee's case of it is roundly mocked. "Impwove twaffic conditions."
- Hitler Ate Sugar: Parodied by the Bots after the judge in the short makes an ominous implication intended for Joe's guardian.Judge: That description fitted someone else I know...if you know who I mean.
- Joisey: The short being produced in the state results in it getting roundly mocked.Judge: Born in New Jersey, eh?Crow: I thought I smelled something.
- Jury Duty: When the judge calls for the viewers to judge Joe, Joel quips "We're stranded in space and we still have to pull jury duty."
- Historical In-Joke: Joe killed James Dean.
- Noodle IncidentAngel: I can't say Joe was out lookin' for trouble, but-
- Not Bad: Even Tom is impressed with one of the car stunts, in which Joe's car narrowly misses two others skidding through a wet intersection.
- Parallel Parking: An early scene has a Match Cut of a car fading into a narrow gap between two cars parked curbside. Tom Servo remarks, "Ah, parallel universe parking." The car's driver has to leave the space the old-fashioned way — as Crow puts it, "He uses the Braille system".
- Rousing Speech: Crow delivers one to the audience (and himself) after being inspired by the short. Subverted at the end, though.
- Sarcasm Mode:Joe: I never hit-and-run!Joel: Well, that changes everything!
Ralph: (staggers to the ground)