Another teacher at Wagstaff, appears to be the teacher for Tina, Jimmy Jr, Jocelyn, Zeke and Tammy. Probably one of the few genuinely normal teachers the school has.
- Hot Teacher: She's a rather pretty woman, and Linda and especially Bob think so; Bob calls her 'ridiculously attractive'.Bob: Why is she a teacher? She should be, like, playing a teacher on TV.
- Only Sane Man: Of the faculty of Wagstaff, given that Ms. Jacobson is the most normal and level-headed one compared to the rest of her colleagues, many of whom are are quirky, morally questionable or just plain crazy.
- Reasonable Authority Figure: She's the only normal teacher in all of Wagstaff who can do her job in teaching the students properly, unlike the rest of the staff members whom have all somehow abused their authority as teachers and occasionally harass the students.
One of the teachers in Wagstaff. She's generally cranky and tough to everyone.
- Early Installment Weirdness: Her voice wasn't as rough in earlier episodes. Admittedly, she smokes, so that might be the reason.
- Vocal Evolution: Her voice was higher pitched and sounded nasally, but gradually became deeper and rougher almost akin to Harvey Firestein.
The librarian and cheerleading coach at Wagstaff Junior High.
- Dork in a Sweater: Generally seen in a blue sweater vest. He's the "not as harmless as he looks" subtype.
- Drama Queen: Tends to overreact until he tires himself out. He wanted to be teaching theater, and when he doesn't gets it, he decided to turn the cheerleader squad into a teenage drama story to satisfy his needs for drama, often sabotaging them.Todd: You are the worst cheer advisor.
- Magic Librarian: Deconstructed Trope in that he doesn't even like books and practices witchcraft out of frustration more than anything else.
- Suddenly SHOUTING!: Basically obligatory when you cast Billy Eichner in a voice role.
- Character Tic: He randomly shout-whispers at people to do things they shouldn't if he's in earshot of the conversation.Mr. Ambrose: Breaking school property? Definitely don't do that. [whispers] Do that! Do that!
Tina's Colleagues and Classmates
Jimmy Pesto's oldest son, referred to as Jimmy Jr. and Tina's crush, first appearing in the season 1 episode "Sheesh! Cab Bob?" Since then he has appeared in several episodes and is often seen at the kids' school.
- Amazon Chaser: He comes to the conclusion "strong girls are hot" at the end of "The Belchies" after he witnesses how Tina's quick thinking saved Louise's life.
- Ambiguously Bi: His wrestling matches with Zeke have a homoerotic vibe, and his feelings toward Zeke could sometimes be seen as attraction. He gets very jealous when Zeke seems to be making friends with Gene. He also greatly admires Josh for his dancing skills when the two of them compete for Tina, and by the end of it he is more into Josh than her.
- Betty and Veronica: The aloof Veronica to Josh's approachable Betty.
- Crazy Jealous Guy: Can quickly become this to Tina or Zeke when he feels pressured.
- Dancing with Myself: He has a passion for dancing his feelings, especially slow dancing, which he doesn't seem to realize is typically done with a partner.
- Depending on the Writer: His treatment of Tina is sometimes horrible and considers her an Abhorrent Admirer, other times, he is friendly and reciprocates her crush.
- Green-Eyed Epiphany: Once he finds out that Tina has Josh courting her, he spends a whole episode trying to woo her.
- Heterosexual Life-Partners: With Zeke.
- Jerkass Ball: In "Presto Tina-O", he acts more abrasively towards Tina, to the point of making her angry.
- Runs with the ball in "V for Valentine-detta" when he not only chooses another girl as his Valentine (Jimmy Jr. and Tina's on-and-off status is standard) but he uses the picture frame that Tina made for him for Valentine's Day to frame a picture of him and the other girl. Speaking of the other girl, he shows up 3 hours late to pick her up for their date, he gets their name wrong, and then he breaks up with her in the middle of the date.
- Know-Nothing Know-It-All: Many times he gets involved in something, but only for the sake of his dancing. He ran for student president just so he can decide what music plays. He became a magician just to show off his dancing. He appears to be even this for dancing, as he never actually takes lessons and just dances based on how he feels, like when he tried slow dancing, something that's done with two people, by himself. He once talked down to Tina that she couldn't keep up with him during a school run, but he himself is a terrible runner, flailing his arms frontward and jumping awkwardly with every step vaguely like he's trying to swim on land.
- Nice Guy: He's generally always a decent, if somewhat dim and oblivious, guy.
- Missing Mom: Like his brothers, his mom is never seen onscreen, though in a few episodes she is mentioned, implying that she may have broken up with Jimmy Pesto Sr. Also in "Family Fracas", his mother isn't shown, although Family Fracas is an event where the kids and both of the parents are supposed to attend.
- In Ex-Mach-Tina, Jimmy Jr. says his mom has a new friend named Allen, indicating shes alive but divorced from Jimmy Sr.
- Oblivious to Love: He has a hard time picking up that Tina's into him, though later episodes suggest that he is at the very least subconsciously aware of it.
- Speech Impediment: Has a very pronounced lisp. Lampshaded by Tina in "The Unnatural".
- Technician vs. Performer: The performer (dances how he feels) to Josh's technician (has been taking ballet for years).
- Those Two Guys: With Zeke.
- Too Dumb to Live: Thinks dancing around wildly with scissors is a good idea.
- Will They or Won't They?: With Tina.
Jimmy Jr's friend and one of the Belchers' schoolmates. He likes to wrestle and is seen as gross by Tina. Initially it seemed like he might become a rival or antagonist to the kids but he has evolved into a companion in their hijinks when a fourth is needed. In those situations, he often serves as the muscle.
- All Men Are Perverts: Zeke loves to talk about boobs.
- Big Fun: He's big, boisterous and energetic.
- The Big Guy: Typically fills this role when he has a storyline with the rest of the kids.
- Blatant Lies: After he was found out to be the Mad Pooper the reason why he didn't get punished is because "[his] family moves around a lot." He never disappears after this is said.
- Boisterous Bruiser: The show doesn't make use of his "bruiser" side much (the Belcher kids go straight to him for their bouncer in "The Kids Run The Restaurant", so it's recognized in-universe), but he is definitely boisterous.
- Bromantic Foil: A variant, where he is often more Tina's foil rather than Jimmy Jr's.
- Class Clown: Until Bob became the substitute home economics teacher and discovered Zeke had a talent for cooking.
- Dirty Kid: He is obsessed with boobs.
- Friend Versus Lover: Although never outwardly stated, Tina's interactions with Zeke seem to imply that she feels like she's competing for Jimmy Jr.'s attention with Zeke. This is mainly one-sided, as the former tends to act cold and distant to the latter, with Zeke being completely oblivious to this — and in fact, seems to like her as a friend just fine. The biggest example would probably be in "The Belchies". Interestingly enough, Tina is generally nicer to Zeke when Jimmy Jr. isn't around.
- Heterosexual Life-Partners: With Jimmy Jr.
- Hidden Depths: As Bob helps him discover, he has a hidden talent for cooking — specifically, he might have a perfect palate, and he demonstrates an aptitude for short-order cooking. The occasional stray comment indicates that he greatly appreciates peoples' trust in him.
- Hot-Blooded: The kind of kid who will jump to action at the drop of a hat. Any action, any hat.
- Karma Houdini: He's the Mad Pooper, but "incredibly, is not in trouble."Zeke: My family moves around a lot.Tammy: His family moves around a lot.
- Large Ham: Just chews scenery every time he shows up. He spends large parts of "Presto Tina-O" not actually doing much, for example, but still manages to have a presence.
- Paper-Thin Disguise: Wears a jockstrap on his face while giving Gene a purple nurple in "Gene It On". Gene is too stupid to tell him apart even when Zeke tells him on the face it's not him.
- Potty Failure: He is revealed to be the Mad Pooper (or the Butt-ler) in "Broadcast Wagstaff School News" — the first time was accident, the second time was for fun, then it was an accident again, and so on, but after that he did it for Tina.
- Remember the New Guy?: In his first appearance, Tina is surprised to see him even though viewers have never seen him before.
- Ship Tease: Arguably done with Tina in "Midday Run". When she helps him get the mascot costume, so he could entertain his grandma before her surgery he is touched by this and saysZeke: Damn, Tina, now I got a story to tell on our wedding day. You think that's not gonna happen, but I'll getcha girl, I'm gonna getcha.
- When he is revealed to be the Mad Pooper, he says he kept doing it for Tina, implying he has a crush on her and attempted to give her source material to write on.
- This is reinforced by Tina's recurring dream in which Jimmy Jr. (her primary love interest) and Zeke switch heads. What's up with that?
- In UFO No You Didnt, Tina believes aliens are coming to end the world and (deeply) kisses both Jimmy Jr. and Zeke. When its revealed the world is not about to end, Zeke asks for another kiss.
- He flat-out tells her he likes her in the Oeder Games.
- Supreme Chef: In "Bob And Deliver", Bob discovers he has a highly acute sense of taste and natural talent at cooking, greatly improving the soup Bob was showing them despite not knowing what most of the spices he was using even were.
- Teen Pregnancy: According to a throw away line from "OT:The Outside Toilet", he was the result of one."Oh, man. This is heavier than my mom at the prom. 'Cause she was pregnant with me."
- Those Two Guys: With Jimmy Jr.
- Wingman: For Jimmy, when trying to woo Tina.
One of the kids' classmates. He first appears helping Bob get better at the video game "Burgerboss" in exchange for Bob protecting him from bullies. He later works with the kids on a number of their schemes.
- Ambiguously Brown: It's not sure what ethnicity he is. Bob thinks he might be black, but isn't sure.
- Bollywood Nerd: It's not stated precisely but Darryl is most likely Indian (as in "from India", not "Native American"), like his voice actor (who was born in America, but whose parents were originally from India).
- Hidden Depths: He turns out to be a talented singer.
- It Is Pronounced Tro Pay: "It's Dar-el".
- The Millstone: In "Fort Night", selling the rest of the kids out to Millie for a bathroom break.
- New Neighbors As The Plot Demands: First appears in "Burgerboss" specifically because Bob needs a video game expert to mentor him. The Belcher kids do not seem to know who he is. But he is subsequently revealed to be a student at the Belchers' school who moves in the same social circles as they.
- Peeping Tom: Has a high-powered telescope he uses to watch his neighbor undress.
A former friend of Tina's and the resident bad girl of the kid's school.
- Alpha Bitch: Acts this way, though she doesn't have the legion of friends you'd expect of the trope. (That Tina was her first friend at Wagstaff should tell you something.) For that matter, she doesn't even really seem at all popular and comes across more like a wannabee Alpha Bitch, given the only people who hang out with her are the Belchers, Jocelyn, Jimmy Jr. and Zeke.
- Disproportionate Retribution: In "Bad Tina", she blackmails Tina into spending time with her and misbehaving by threatening to give Jimmy, Jr. an erotic story Tina wrote about him. Then when Tina fails to show up for a double date and ruins Tammy's chances with Zeke (because Tina got grounded for trying to sneak out in the middle of the night with a bottle of margarita mix, using the family's emergency phone to text Tammy, and calling Linda a boob punch), Tammy decides to read the story to the entire school.
- Dumb Blonde: She's not a natural blonde, but she's definitely stupid enough to qualify when she does go blonde.
- Excessive Evil Eyeshadow: Well, she's not exactly evil but she is bitchy and she her eyeshadow makes her stand out when it comes to the rest of the cast
- Foil: To Tina. While Tina is a weirdo who comes a struggling working-class family, she's also a Nice Girl. Tammy is a "normal" girl from a wealthy family, and is a complete jerkass.
- The Friend Nobody Likes: She's often seeing hanging out with Jocelyn, Jimmy Jr and Zeke, but neither one of them appear to be all that fond of her.
- Friendly Enemy: Tina is still very cordial with her, which angers Tammy. However, this is later subverted when Tina starts actively fighting back against her, but this doesn't stop them from working together when it's needed.
- Go-Karting with Bowser: Seems to be her relationship with the Belcher kids. Even though they're rivals they occasionally team up, like when Gene joined her cheer-leading squad.
- Gasshole: She tends to be quite flatulent, and probably the most flatulent character on the show, as she not only farts when she laughs too hard, but also when she's lifted during a cheer-leading routine (or whenever she's lifted 'wrong' as she claims), and when she's really nervous like when she snuck into a high school party.
- In "Sleeping With The Frenemy" she practically turns into a fart machine whenever she sleeps, or as Tina calls it 'night farting', but Tammy denies this, only to immediately start farting upon falling asleep.
- Hidden Depths: She might be a pompous, self-acclaimed popular girl with the confidence to boot, but even she has moments of being just as nervous and awkward as Tina, as shown where she couldn't even speak to an older, taller high school boy at a high school party.
- Hypocrite: She accuses Tina of copying her when both girls show up to school wearing the same bracelet in "The Runway Club", but 2 seasons later in "Teen-a Witch", she outright steals Tina's idea of a costume to use in a contest.
- In a recent Season 8 episode "Sit Me Baby, One More Time", she has the nerve to call Tina a bully just because she called her 'horrible' (which isn't untrue), when Tammy herself has called Tina plenty of mean names and done far worse bullying to her, granted, Tina did display a more abrasive side in this episode but still, the fact that Zeke backed Tammy up did not help.
- Informed Judaism: Her Bat Mitzvah episode is the only indication she's Jewish, otherwise she fits the stereotype of the spoiled WASP.
- Jerkass: Blackmails Tina on a frequent basis, is a total stuck up, a spoiled rotten brat, and not a nice person at all in general, as she finds doing mean things to people hilarious and when push comes to shove, Tammy would rather help herself even when her friends or other things important to her friends are on the line.
- Jerk with a Heart of Jerk: She'll only be friendly when you happen to have something she wants. And not even that will save you from her awful attitude.
- Jewish American Princess: "Mazel Tina" reveals she's Jewish.
- Karma Houdini: Unlike some of the other characters in the show, this tends to be averted. Fate always seems to turn the tables on Tammy, one way or the other (most of the time).
- Kent Brockman News: In her second appearance and now a regular trait with her as seen in "The Millie-churian Candidate".
- It's All About Me: Her ideal theme for her Bat Mitzvah? Herself.
- Lack of Empathy: She is aware of her own feelings and insecurities, but calls out Tina for hurting her feelings when the latter called the former 'horrible', however, Tammy can't seem to comprehend that Tina herself has insecurities and feelings that Tammy has hurt plenty of times.
- Large Ham: Tammy loves to chew the scenery.
- Never My Fault: When it comes to farting, she almost always tries to deny it or blame it on someone else. It's sort of running gag at this point.
- New Transfer Student: In her first appearance.
- Not So Different: She and Tina have actually ended up bonding more than once, mostly over boys, and Tina has gradually become more equally aggressive in their rivalry. There are some hints that Tammy actually likes Tina, but is too petty and jealous to actually be her friend.
- Parental Neglect: Downplayed. While they aren't outright neglectful, what we've seen from her parents implies that while they do appear to love Tammy, they're not all that attentive of her, as in "Mazel Tina" despite them claiming that they were looking for her, the mother putting her drink down more or less implies that they were doing the exact opposite.
- In fact, her parents are pretty much the exact opposite of the Belcher parents Bob and Linda, whom pretty much go through hell for their kids, as in "Sleeping With The Frenemy" Tammy's father showed and stated that he wasn't willing to take a medevac to retrieve his daughter when she was left behind from a cruise because of his airsickness, and Tammy's mother didn't seem that bothered by their daughter being left behind.
- Small Name, Big Ego: Tammy acts like she's a super popular Alpha Bitch, but it seems the one person who's both aware of her and actually likes her is Jocelyn, and even she doesn't seem to like Tammy very much.
- Spoiled Brat: Is yelling at her mom over the phone in "Mazel Tina", and at her rabbi. And in general she feels entitled to anything she wants, is used to a cushy-life style while she makes fun of others who don't have what she has, has high standards and doesn't even know what the word 'work' means.
- Teens Are Short: Even more so than Tina; she's barely taller than Louise.
- The Rival: To Tina, though she's actively more aggressive than Tina (at least until Tina starts fighting back in later seasons).
- Ungrateful Bitch: In 'Sleeping With The Frenemy' while Tina had an ulterior motive to get her generosity Thundergirl badge, it was pretty darn generous of her to let Tammy stay at her house while she was accidentally left behind when her parents went on their cruise, however, Tammy acts like a complete brat and criticizes everything the Belchers do for her, including Linda's cooking and when Bob dries out her hair, and not once is appreciative of their efforts or for the fact that they opened her into their home (reluctantly, but still).
- Unusual Euphemism: "Don't be such a boob punch!"
- You Don't Look Like You: In her first appearance, she was a brunette, but she dyed her hair blonde in her next appearance, which stayed that way for the rest of the series.
A recurring classmate of Tina and Tammy.
- Bare Your Midriff: Her purple t-shirt shows her navel.
- Brainless Beauty: She isn't very smart but many boys apparently find her attractive as seen in "The Gene and Courtney Show" where she had gotten 4 Valentines' Day cards.
- Cloud Cuckoolander: Not only does she seem moderately unintelligent, but she once pulled the fire alarm when she witnessed a fight because she assumed the Fire Department would know what to do.
- Dumb Blonde: Extremely shallow, she has very few opinions of her own.
- Girl Posse: An extremely poor man's one to Tammy, even though the two don't actually seem to like each other all that much.
- Nice Girl: Despite her lack of intellect and the fact that she tends to follow Tammy in an attempt to be popular, Jocelyn herself is a pretty docile and friendly girl.
- Only Friend: The only person shown to actually like Tammy, who annoys even her own family.
- Strong Family Resemblance: Her mother was shown in "Runway Club" — not only do the two have a strong physical resemblance, they even speak and behave in the same manner.
- Toxic Friend Influence: Tammy brings out her nastier side.
- Valley Girl: She speaks with the stereotypical "valley girl" accent, adding "-uh" to the end of most of her sentences.
Quite possibly the only student at Wagstaff Elementary who is even dorkier than Tina.
- Alliterative Name: Henry Haber.
- Amazon Chaser: Henry immediately asked Tina out after she showed her fiery and passionate debating skills.
- The Chessmaster: During the school elections, he manages to successfully predict and manipulate the actions of both Millie and Louise, leading to their both being disqualified, leaving him as the only remaining candidate.
- I'm Standing Right Here: Such a beige, boring guy, that people tend to not notice him standing right in front of them.
- Insufferable Genius: Henry has a tendency to be extremely unpleasant to others due to thinking he's smarter than everyone else.
- Nerd: A textbook example; a complete dork in nerdy, boring clothes who's obsessed with dinosaurs and his fighting robot graphic novel. Is also incredibly intelligent and observant and is not afraid to use it to his advantage.
A very intelligent girl with a talent for science that gets partnered with Tina.
- Bollywood Nerd: Her name implies she's South Asian, and she's one of the smartest characters so far.
- Good Counterpart: She's essentially the nicer version of Henry Haber, meaning she has none of his manipulative trends and is actually able to socialize and befriend others, but is still extremely smart.
Gene's Colleagues and Classmates
A girl in Gene's grade who like likes him. To spare her feelings, Gene agrees to go out with her, to all three kids' — and Bob's once he meets her — annoyance. She has a heart condition that requires medication every day.
- Abhorrent Admirer: To Gene.
- Alpha Bitch: Though not as bad as Tammy. Definitely more "annoying" than "bitch". Becomes a Lovable Alpha Bitch in the sixth season.
- Character Tic: Sucking on her necklace
- Crossdressing Voices: Voiced by David Wain, better known from The State and as the voice of the Warden on Superjail!.
- Derailing Love Interests: Inverted. She is introduced as a selfish, self-centered and annoying girl who annoys the Belchers as a whole and pushes Gene to be her boyfriend. By her reappearance in season 5 premiere "Work Hard or Die Trying, Girl", she is still not in quite good terms with Gene, but is generally nicer to him at the end and shows genuine regret for some of her actions. "The Gene And Courtney Show" has her as a Spoiled Sweet girl with whom Gene rekindles a romantic relationship, she has gotten so better that their relationship is steady and healthy, with them breaking up because they couldn't work and date simultaneously.
- Girl Posse: Has two other friends she is usually seen with.
- Hidden Depths: She's not too bad of an actress.
- Ill Girl: Played with. She has a heart condition which makes faking a heart attack played quite realistically — the heart attack was fake, but the problem was real. Health-wise though, besides that, Courtney's not that much different from any other girl her age.
- It's All About Me: About as much as would be realistic.
- Jerkass: Downplayed but clearly there.
- Jerkass Has a Point: When Gene finds out Courtney's dad works in advertisement, he continues seeing her because he thinks he can get a jingle used in a commercial. He then tries to use her birthday party to pitch something and gets so mad at Courtney his screaming causes her to have a heart attack. She gets back at Gene by having her dad and doctor pretend that she dies. From that point the two seem amicable after Gene apologizes for using her even though Gene has to help set her up with another kid.
- Lack of Empathy: Downplayed — she has some empathy, but is a Spoiled Brat. Averted in the sixth season.
- Official Couple: With Gene for the duration of The Unbearable Like-Likeness of Gene.
- The Rival: To Gene in Work Hard Or Die Trying, Girl. Unlike her fellow blonde rivals Tammy and Millie, Courtney and Gene do get along a little better.
- Spoiled Sweet: Becomes this in the sixth season.
- Took a Level in Kindness: While still in an "antagonist" role and something of an irritant, she is far less obnoxious in her appearance in Work Hard Or Die Trying, Girl. Comes to a head in the sixth season when she moves firmly out of the antagonist role doing the morning announcements with Gene. The two enter a relationship again that is mutual on both ends, but it is Courtney who decides they need to break up because it's negatively effecting their performance. After Gene does a heartfelt song about Valentine's Day and demonstrates he respects Courtney's choice, she gives him a kiss, saying it is Valentine's Day.
- Worthy Opponent: Despite not initially getting a role in Gene's musical, she expresses open heartfelt admiration when she sees in it action.
- The Runaway: In his first appearance, he convinces Gene to run away with him as he tries to get away from his parents extremely healthy new habits that had been bothering him.
Louise's Colleagues and Classmates
Jimmy Pesto's younger twin sons, who are overly-attached to each other.
- Ambiguously Gay: They're occasionally suggested to be attracted to each other.
- Berserk Button:
- Being separated from each other.
- Mistaking one twin for the other.
- Color-Coded Characters: Andy wears a dark mustard yellow shirt while Ollie wears a sky blue shirt.
- Cloudcuckoolanders: They say and do random stuff.
- Cute, but Cacophonic: Both of them, but Ollie's voice can come off as the more grating of the two.
- Expy: They seem to be of Walter and Perry from Loren Bouchard's previous show Home Movies, with both sets being Cloudcuckoolanders in a bizarrely codependent and vaguely romantic relationship.
- The Dividual: To the point where being assigned separate partners on a field trip causes them to have an emotional breakdown.
- Don't Split Us Up: They threw a temper tantrum when they weren't assigned to each other as partners in "Carpe Museum".
- Finishing Each Other's Sentences
- Missing Mom: Their mother is never seen. It's implied their parents were divorced.
- Single-Minded Twins: Both of them think alike.
- Those Two Guys: And they hate being separated from each other. As shown in "Carpe Museum", they will both throw a tantrum if this happens.
- Twincest: Implied in a very G to PG rated way.
- Twin Telepathy: Implied, considering one of them can feel it when Louise attempts to steal the other one's candy out of his pants.
A sweet, dorky boy who goes to school with Louise, frequently in trouble due to his awkward combination of thrill-seeking tendencies and severe asthma. He originally appeared as Louise's field trip buddy in "Carpe Museum" and sneaked into a closed rainforest exhibit with her.
- Adorkable: A nerd and somewhat awkward but with all around endearing personality.
- And Zoidberg: "AND RUDY'S... there!"
- Beware the Nice Ones: Once he finds out that Tina lost Zeke, when she was suppose to escort him to the principal, and lied to Mr. Frond, saying she did. He is upset with her, and sabotages her attempt later to cover up her mistake.
- Broken Pedestal: Saw Tina as this "Midday Run"
- Challenge Seeker: Regularly participates in activities far too strenuous or risky for a child with asthma, apparently specifically because someone told him not to. This includes tree-climbing, baseball, sneaking off during field trips and train robbing. He's a bit of an adrenaline junkie.
- Companion Cube: Beanbag.
- Crazy-Prepared: "You never know when someone will want to jam."
- Determinator: Serious asthma doesn't stop him, actually, he seems to be determined to do more in spite of it.
- Exactly What It Says on the Tin:Bob, incredulous: Regular-Sized Rudy? Why do they call you that?
Rudy: Just look at me.
- He's called this to differentiate him from Pocket-Sized Rudy, who is apparently the size of a baby if his height compared to Louise in "Carpe Museum" is any indication (he's too short to appear on screen when the camera is eye-level with Louise).
- Expy: He heavily resembles Bobby Hill.
- I Just Want to Have Friends: And will risk asthma-related death to keep up with them. The Belcher children (Louise in particular) like him.
- Ill Boy: He has pretty severe asthma and he'll die if he doesn't have his inhaler every two hours.
- In-Series Nickname: As opposed to Pocket-Sized Rudy.
- Masculine Girl, Feminine Boy: The timid, quiet Feminine Boy to Louise's Masculine Girl.
- Morality Pet: To Louise, on occasion. She seems to genuinely like him.
- Nerdy Inhaler: Not all that nerdy, but still needs a hit o' inhaler every couple of hours or else.
- Nice Guy: Unusually low concern regarding his own mortality aside. Louise is shocked during The Kids Rob A Train when he convinces her that his offer to pull the stolen chocolate into the juice caboose and then help her up is genuine, and not an attempt to double-cross her. She even states she can't work with someone who wouldn't take the obvious chance to double-cross someone.
- Non-Action Guy: Emphasized in "The Unnatural", when he takes the baseball scam class and falls down gasping from hitting an imaginary ball.
- Only Known by Their Nickname: "Regular-Sized Rudy"/"Reg-Size Rudy". He's called this because there are two Rudys in the school, with the other one being called Pocket-Sized Rudy. He likes his nickname, while Pocket-Sized Rudy doesn't like his.
- Puppy Love: "Bob Actually" shows that he likes Louise as more than a friend, originally trying to ask her out to lunch on Valentine's Day. This was a Red Herring, as Rudy wanted her to give a Valentine's card to Chloe Barbash. However, Rudy did get a kiss from Louise after she told him Chloe was just using him, and he did enjoy it.
- Rimshot: Supplies Louise with a cymbals-only sting after she insults Mr. Frond.
- Sixth Ranger: The child most often to join the Belcher kids on their misadventures.
- Strong Family Resemblance: As seen in "The Kids Rob A Train", Rudy greatly resembles a smaller version of his father, but with no glasses.
Student of Wagstaff and Schoolmate of Louise. Attended Louise's ill-fated sleepover in "Slumber Party"
- Blatant Lies: Harley tells Louise that she'll trade stickers with her, but that her stickers are really rare, so one of Harley's equals six of Louise's.
- Innocently Insensitive: Louise spins a story about Gene's feral twin biting off her buttcheek in order to get Harley to leave. Her response?Harley: Is that why you dance weird in dance class?
Louise: Shut up, Harley.
- Motor Mouth: Louise quips that Harley "Hard-ley ever shuts her mouth".Harley: Louise, what are your ten favorite colors of dogs? Mine are red, brown, spots, black, white, orange spots, kinda-brown, kinda-black, brown spots, black spots, red spots, red stripes..."
- Oblivious to Hints: Harley can't tell that Louise hates her guts.Harley: I made an orange and yellow tie-dye, because my cat is orange and yellow! And my cat's name is Popover. What's your cat's name?"
Louise: My cat's name is 'I don't have a cat, stop talking to me right now, Harley!'"
Harley: Aw, so cute! Where is it?"
Student at Wagstaff, Schoolmate of Louise and member of Thundergirl troop 119. Attended Louise's ill-fated sleepover in "Slumber Party" and was a possible suspect for the mole in Troop 119 in "Tina, Taylor, Soldier, Spy"
- Nerd Glasses: Louise threatens to flush them down a toilet in "Tina, Taylor, Soldier, Spy".
- Passionate Sports Girl: Played With. Despite her crippling germ phobia, she's a Thundergirl, which requires camping outside, tried out for field hockey, and is on Harley's soccer team. On the other hand, while we don't see how field hockey went, she's not very good at soccer or being a Thundergirl, probably because of her neuroses.
- Sickly Neurotic Geek: Textbook example.
- Super OCD: Will do anything to keep away from germs or dirt. Doesn't seem to have a problem playing sports, though.
- Terrified of Germs: Defining character trait. Has never sat on a toilet seat. Or any seat.
A classmate of Louise's that appears for her sleepover. She's considered painfully boring by everyone, but she turns out to be much more than what first seem.