Theme Twin Naming: Their names sound the same but use a letter similar to their respective horn designs.
Scott "Squishy" Squibbles
Voiced by Peter Sohn
Adorkable: Just look at him. It helps that he resembles Russell, who just so happens to be inspired by Squishy's voice actor, Peter Sohn.
Always Someone Better: It's not that evident at first, but he could count as this to Mike. Though conventionally shorter and cuter than Mike, he ends up becoming an on-field Scarer. This is to demonstrate that it wasn't exactly height and appearance that doomed Mike's dreams.
A preppy fraternity comprised only of the cream of the crop in scare students, Roar Omega Roar has won the Scare Games several years running. Sulley was a member with them at the start of the semester until getting thrown out of the Scare Program. Randall Boggs becomes a member of the group for the Scare Games in the film.
Jerkass: Seriously, he takes away Sulley's jacket just because he felt like Mike would show him up and wanted Sulley to prove he was better then him. This was after Mike had abandoned interest in his fraternity.
Karma Houdini: Other than losing the Scare Games, his mean-spirited actions aren't shown to have any consequences and it seemed he moved onto a decent career at Fear Co.
He does get some retribution in the short Party Central.
Unless you take Fridge Logic into account: Sulley changing Monsters Inc.'s M.O. from scaring kids to making them laugh (and the subsequent increased energy supply) would have easily outperformed the rest of the fear-based power companies, putting Johnny out of a job (Unless he knows how to make kids laugh, which is doubtful).
The Nicknamer: Examples include "Killer", "Big Blue", "Bruiser", and "Grandpa". He also latches onto "Sulley" immediately when he's told that's his current conversation partner's preferred address. Which says a lot when you consider that Randall is just "Boggs" to him.
Obviously Jerkish: His rather devilish appearance should be a big hint that he's not a nice guy.
Villain Has a Point: An unpleasant take where in spite of his brutal jerkishness, he is ultimately right that Oozma Kappa lack the traditional Scarer traits. This does leads to Oozma Kappa learning to become resourceful about their own seemingly benign traits to become Scarers.
Nice Job Fixing It, Villain: If Chet hadn't casually mentioned to Mike after he and the rest of Roar Omega Roar humiliated them at a party that they weren't cut out "for the big leagues", Mike wouldn't have gotten the idea to take Sulley and the rest of the Oozma Kappa members to Monsters Inc. to cheer them up, show them that all kinds of monsters are scarers, and thus provide them the encouragement they needed to proceed forward in the Scare Games.
Armor-Piercing Question: Gives one regarding Mike, that Sully (despite starting to warm up to Mike) can't give a straight answer to.
Hardscrabble: Do you think he's scary?
Berserk Button: Surprisingly subverted. When her record-breaking scream canister is introduced, and summarily knocked over and broken, it seems as though Hardscrabble is about to enter Dissonant Serenity mode and tear Mike and Sulley a new one. But she doesn't. She's disappointed, but she never so much as raises her voice.
Having said that, she doesgive both Mike and Sulley a "The Reason You Suck" Speech, instead of giving them a fair go in the scream simulator.
Big Entrance: Loves doing these. Anytime she's shown flying into the scene, everyone noticeably becomes nervous and on edge. In particular, her introductory scene leaves absolutely NO room for discussion about her qualifications as a Scarer.
Establishing Character Moment: Her first scene has her swoop into the classroom, pull down all the curtains and make the room very dark, stand by her bust and trophy to show her earned credentials, and give a stern lecture about how she expects only great things and anyone substandard will fail.
According to an interview, Dean Hardscrabble takes much inspiration from Maleficent. The artists even gave her Maleficent-style horns at one point in development, but ultimately decided that this was going too far.
Kick the Dog: Although she stays rather reasonable in her strictness, she's not immune to those moments and even gently taunts Mike after Oozma Kappa's near-loss in the first round. Granted, her grudge against him is understandable, but her flaw is that her criticisms are more unpleasant than helpful.
Not So Stoic: She's the sternest, strictest, and most unflappable monster in the school. But when Mike and Sulley create a scream of such power that it not only activates a door from the human side, but fills up every scream canister in the laboratory until they and the door explode, she goes into wide-eyed shock. Later, as she bids them good luck in their future endeavors, she informs that she believes in them because they did the one thing she thought was impossible: surprising her.
Obviously Evil: Come on, she's basically a black and red centipede/dragon hyrbid. Subverted though.
Reasonable Authority Figure: She holds a grudge against Mike and Sulley for breaking her scream canister and she's often unpleasant to Mike about his endeavors. Still, she manages to be reasonable since she enforces fair punishment and still permits them a chance of redemption at the Scare Games and does not let Oozma Kappa suffer for the actions of Mike and Sulley.
Stern Teacher: She's more harsh than actually cruel and offers words of encouragement to Mike and Sulley as they leave MU.
Tranquil Fury: When Mike and Sulley accidentally knock over and break her record making scare canister. She's surprisingly rather calm about it, stating it was fine as long as no one got hurt. Mike lampshades this...at least before she gives her impromptu tests to the two.
Tough Love: This may be an interpretation of her behavior towards her students.
Villain Has a Point: While not quite a villain, she and all other doubters are later proven undeniably right in telling Mike he's not scary. In addition, when she dresses down Mike and Sulley, both fail her hypothetical scenarios, Mike for the above reasons, and Sulley because he doesn't use his head when scaring, implying both Mike and Sulley only sped up their inevitable failure in the school.
She has fair reason to bear a grudge against Mike and Sulley for breaking her canister and notably aims her disdain directly toward them rather than the rest of Oozma Kappa.
Her extremely demanding requirements for being a scaring major also make sense in-universe. Being a scarer, according to everything the monster world understands, is incredibly dangerous. You don't want incompetents going into what is treated as an extremely dangerous environment.
Not only dangerous for the scarers themselves, but, as she informs Sulley, a botched scaring expedition could literally lead to the end of civilization if the humans discover the Monster World.
Retired Badass: Not quite as much as Hardscrabble, but his Scare Card shown during the credits appears rather old in comparison to all the others, showing that he was a very successful Scarer before becoming a teacher.
Stern Teacher: He gives off a strong no-nonsense vibe at first, but he is genuinely very impressed over Mike efforts and diligence.
Disproportionate Retribution: To anyone who make a noise in her library as shown when a student make a scuffing noise as he's leaving a table, even though it wasn't intentional. She quickly grabbed him and threw him through an open skylight where he landed in a pond outside, showcasing what the participants of the games were in for if they were caught.
Friend to All Children: Frank is the only one of the Scarers at MI that actually stopped to talk to Mike's class when they were visiting. He even gives Mike his trademark MU cap as a gift.
Nice Hat: His trademark MU baseball cap, which he ends up giving it to Mike.
Small Role, Big Impact: He only appears in the opening scene, but he leaves a huge impact on Mike and inspires him to pursue Scaring as a career. Mike's scaring style is greatly influenced by Frank's — for example, the technique of waking a child up by slowly scratching your claws against the bedpost.