Waternoose proudly states early in the film that his family has run Monsters, Inc. for three generations, but he fears that the company will collapse under his watch due to the worsening energy crisis. When he resorts to kidnapping children and trying to forcefully take their screams, is he genuinely doing it to help the people of Monstropolis, or just trying to save the company and his own reputation?
While he's much less enthusiastic about it than his associate, it's implied that Waternoose was still the mastermind of the plan and hired Randall to carry it out. Or it might still have been Randall's plan, and he convinced Waternoose to go through with it. Does this make Waternoose a Well-Intentioned Extremist forced to stoop to Randall's level, or just as unapologetically cruel and heartless as Randall himself?
The scene of Sulley watching (what he believes is) Boo being mutilated by the trash compactor. Like the Looney Tunes short it's referencing, there's obviously nothing funny about a child being brutally killed, but Sulley's melodramatic reactions to what we explicitly know isn't happening take it from tragic to hilarious.
Randall beating the crap out of Sulley and almost choking him to death? Terrifying. Mike being completely oblivious to this and making a rambling apology as Sulley's being choked to death? Hilarious!
Draco in Leather Pants: A good number of Randall's fans are convinced that he was just stressed out and didn't really do anything wrong. The more extreme ones see him as an orphan who's discriminated against for being a reptile, both in-universe and out. As Disney will tell you, any type of material that contradicts these views is immediately deemed non-canon or just ignored.
George Sanderson has a lot of people who feel bad for him being a victim of two 2319s. In the end, they were glad to see he got his justice.
Epileptic Trees: Boo is the central figure of the Pixar Theory, that all the studio's films share the same universe. It states that she became obsessed with reconnecting with Sulley and discovered an erratic form of time travel that resulted in the Easter Eggs in all the other films, eventually becoming the witch from Brave and causing the introduction of magic into the world in the first place.
Randall's behavior in the original film becomes worse, not to mention much pettier, when you watch the prequel and realize that for months, if not years, he'd been beaten out as Scare Leader by what essentially amounts to a college dropout.
Randall's nastiness towards Mike also becomes this after said prequel as well: not only did they used to be roommates and friends, Mike's advice to Randall to use his invisibility is what helped him become such a good scarer in the first place. Even later coming close to killing Sulley.
Not to mention, Mike's bitterness over the possibility of losing his job reflects all the hard work and turmoil he had to go through to have his job as a Scare Assistant.
Boo narrowly avoids being crushed to death into the shape of a cube. But in Cars 2, this is precisely what happens to Leland Turbo.
He Really Can Act: Billy Crystal is most well-known for his comedic work, but he delivers Mike's emotional dialogue heartbreakingly realistically, particularly Mike's monologue to Sulley when they're trapped in the Himalayas.
Heartwarming in Hindsight: The prequel also revealed that Sulley and Mike weren't always friends, with the duo having sort of a bitter rivalry. Although they do end up warming up to each other by the end of said prequel, this is the flick that really shows just how much their friendship has evolved.
In the outtakes, a character accidentally calls Sulley "Solomon" and is called out for his mistake. Now rather amusing to those who have read the NES Godzilla Creepypasta and are familiar with the Kaiju named Solomon there
In the teaser trailer, Sulley says to Mike "You remember the fifth grade, when you spent all your time sending notes to Susie Boyles? The rest of us were studying geography." Monsters University reveals that not only did Mike and Sulley not meet until college, but Mike was a diligent student while Sulley spent most of his time partying.
In the charades trailer, Sulley correctly guessed Mike's charade as Star Wars. 11 years after the film came out, Disney, the parent company of Pixar, bought the rights to Star Wars.
Towards the beginning of the movie, Mike calls Sulley (voiced by John Goodman) "Big Daddy." A few years later, in The Princess and the Frog, John Goodman would voice ANOTHER character nicknamed "Big Daddy."
Roz is the leader of the CDA. Making this worse is that she appears in Monsters University in her CDA armor, and her voice (also provided by Bob Peterson) is unmistakable.
Jerkass Woobie: Waternoose, up until he crosses the Moral Event Horizon, is doing what he does out of genuine concern for the monster world and has real fatherly affection for Sulley, feeling clear regret over having to betray him.
Waternoose's line, "I'll kidnap a thousand children before I let this company die!" is subject to snowclones/Photoshops on Tumblr and other sites.
The line is even more popular among Latin American audiences. For the film's Mexican Spanish dub, the quote was dubbed as ¡Robaré los necesarios para salvar esta compañía! (I'll steal all the kids I need to save this company!) leading to its extensive use in discussions regarding politics and other real world issues, as well as a far more conventional meme mocking things such as reposting memes and stealing them from other pages.
Also popular in the Latin American countries and related to the dub is the line "Well, a kid flew right over me and blasted a car with its laser visionnote Translated as Un niño flotó sobre mí y voló un auto con su rayo láser." Though this is mostly due to the Argentine-like accent used for the character rather than the actual line.
"Put that thing back where it came from, or so help me!"
"Wazowski, you didn't file your paperwork last night."
Covering Mike's face on any packaging he appears on has bled out into reallife. Occasionally followed up with variations of "I can't believe it... I'm in a (object with Mike Wazowski's face covered on it)!".
"You and I are a team. Nothing's more important than our friendship," thanks to its prominence in Baby Driver.
"Stop feeding me lines from Monsters Inc!"
Way too many of Mike's scenes to count. Pretty much everything he's done has become a meme at some point.
A Photoshop of Sulley's face on Mike's body has become popular as a reaction to "bruh moments".
"Do you hear that? It's the winds of change..."
The iconic Power Walk of the Scarers has become this in the wake of the 2020 COVID-19 pandemic. Captions over the video usually go along the lines of "girls returning to the salon once quarantine lifts", or "how everyone will be when they get to go to the club again".
Another COVID-19 related meme is to reference "23-19" as a way to poke some much-needed jest at the panic induced by the rapid spread of the virus.
During Election Week 2020 when votes came in far slower than usual thanks to the increased amount of mail-in votes, many memes went around comparing the wait for the final results to Sulley and Randalls shifting vote tallies during the first Scare Floor sequence. This also led to memes about Sullivan 2020 and the like.
Randall and Waternoose's plan, which involves kidnapping children and using the Scream Extractor to suck the screams from them, which if the effects on Fungus are considered standard, would kill them through suffocation by sucking the very air from their lungs along with the screams.
Speaking of which, if Randall didn't cross it by planning the above, then he crossed it by trying to use the Scream Extractor on Mike.
And if this wasn't bad enough, Waternoose corners Sulley and Boo in the climax and makes it clear that he intends to straight-up murder them because they know too much. In his own words, "I'll kidnap a thousand children before I let this company die! And I'll silence anyone who gets in my way!"
Doubles as a TearJerker, because Sully considered him a father figure.
No Problem with Licensed Games: Monsters, Inc. Scream Team for the PS1 and PS2 is one of the many copycats of Super Mario 64, but instead of lazily rehashing the basic concept to make a quick buck the developers instead opted to produce wonderfully unique levels to give each world its own feel; in other words, they copied Super Mario 64's methods, but kept the final product its own distinction from its competitors. It also helps that the game has a very snazzy jazz soundtrack and stellar graphics for its time.
Abominable Snowman only has a brief scene, but remains one of the most well-liked characters in the movie. It no doubt let him being brought back in Monsters at Work, where he got a happy ending
The mother and son living in the trailer who mistaken Randall as an alligator after he is banished to the human world. Though only their silhouettes are shown, they are rather popular in their brief appearance, especially the mother for beating up Randall with a shovel. Their popularity also led them to return in Kingdom Hearts III, reenacting the same karmic justice on Randall after he is defeated.
In the Latin American dub, the purple monster in the TV interviews saying that the kid blasted a car with its laser vision. Mostly due to the completely out of place Argentinian accent the actor gave it. To the point it is very easy to find remixes of that minor scene in Spanish.
Popular with Furries: Though not animals per se, several monsters like Sulley and Randall are popular among furries for their animalistic traits.
The Problem with Licensed Games: While Scream Team is a pretty well regarded 3D platformer in its own right, the same can't be said for the far more obscure PS2-exclusive Monsters, Inc. game, which has ugly graphics that look about on par with a PS1 game, poorly designed platforming with extremely difficult sections early on in the game (the second level features a mail train segment which lasts a long time and instantly kills Sulley if he falls at any point while the third level has a chimney segment which requires pinpoint-perfect reflexes and accuracy and also has a segment that will take you right back to the beginning of the level without telling you), demotes Mike to an NPC and has No Ending.
Notice that the Big Bad's plan is essentially to kidnap children and use them for slave labor...
Also when Sulley thinks Boo is being crushed by the trash compactor.
Rooting for the Empire: Although many fans can agree that it's hard to hate Sulley and Mike, many fans (particurally female fans) found themselves rooting for Randall over said characters to the point where some were disappointed that he didn't win in the end.
Owing to its plethora of colorful monsters and creatures, not to mention the presence of Frank Oz, this has been called "the best Muppet movie never made by Jim Henson". Fitting, as Pete Docter is a huge Henson fan and even considered being a Muppeteer before getting into animation.
It's also considered to be the best animated (and, by extension, best kid-friendly) movie The Coen Brothers never made, not only due to their regularstars appearing in this but the plot wouldnt be out of place in their works, either.
Unintentional Uncanny Valley: Impressive as it was at the time, the CGI has not aged all that well. The lighting still makes everything look kind of plastic, and Boo looks more like a doll than a human, something Pixar still hadn't quite nailed by 2001 (though you can blame two Toy Story movies for that). Compare this to Monsters University immediately before or after, a movie where Pixar actually changed their lighting system to achieve better visual effects.
Unpopular Popular Character: Randall Boggs. In-universe, with the exception of Fungus and Waternoose, the characters don't take him too seriously and he's quickly over-shadowed by Sulley. The fans, on the other hand, consider him one of (of not) the best Pixar villains due to how malicious he is, his determination and his sympathetic potrayal in University. It helps that he's voiced by Steve Buscemi (who's known for playing violently deranged characters with bad tempers).
Visual Effects of Awesome: Probably not as impressive today, but when the technology of CGI was still relatively at its bare minimum at the time, great pains were taken to make Sulley's fur look real. That's not even mentioning Randall's disappearing acts.
What Do You Mean, It's Not Didactic?: Due to focusing on a company, there's a lot you could read into this movie about energy use, humane treatment, and the rights of whistle blowers if you think too hard about it.
Woolseyism: In the outtakes in the German dub, the joke of Sulley flubbing a line leads to a good one: when trying to confess to Mike about the human child he's hidden in the bag, Sulley accidentally says "Flasche" (bottle) instead of "Tasche" (bag). Mike quips, "Well, unless you have a script where Boo appears as a genie.".