- Voiced by: Katie Crown
Another teacher at Aberdale Elementary, she seems to put very little effort into actually doing her job.
- Big Eater: Is seen devouring a plate of wings in "Turtle Hats".
- Child Hater: If her actions in "Lost Playground" are any indication (she took a bit too much glee in taking away the kids' recess).
- For the Evulz: Some of the things she does is because of this trope
- Freudian Excuse: According to a flashback to her childhood in Lost Playground, we find out that when all the other kids went outside to play during recess, her mother, Millie, who worked at Aberdale Elementary before she did, would never let her play outside, telling her that it was too dangerous and that she'd hurt herself.
- Fat Bastard: Big, plump, mean to practically anyone, and an incredible buzzkill.
- Fun-Hating Confiscating Adult: She has the ENTIRE playground confiscated when one of the kids is hurt.
- Gasshole: Rips a mighty fart in "Freedom Cactus", immediately after claiming that "flatulence is to be done in the bathroom, in private".
- Good Is Not Nice: She is a mean-spirited sadist who does whatever she can to foil the students' plans, but all the same she really does care about them, as she rescues Clarence from West Aberdare Elementary in "Field Trippin'".
- Jerkass: Probably the biggest one of any regular character; she doesn't seem to pay the kids any mind in "Average Jeff", she seems to punish children for odd reasons (giving Percy detention because he cried too much after falling off the swing, for instance), she is an incredible buzzkill (see Child Hater and Moral Guardian), and even gets away with drawing a food graffiti insult directed at Mr. Reese.
- Jerk with a Heart of Gold: Despite her sourpuss attitude, she really wants everyone to be safe, as shown in "Suspended."
- Karma Houdini: Gets away with committing vandalism on Mr. Reese's car with the marinara sauce from the spilled meatball sub, not even ending up on Reese's list of suspects. (Belson was the one who Mr. Reese instead accused.)
- Moral Guardians: From playgrounds to innocent comics of a cactus farting, she'll find anything offensive.
- Sadist Teacher: She punishes kids for tiny reasons.
- Supreme Chef: Makes her own canned beans, which are apparently quite delicious. Don't expect her to put them on the market, because she just makes them for her personal consumption, and there will be heck to pay for anyone who tries to mess with her beans.
- Troll: She vandalizes Mr. Reese's car with an insult directed towards him.
- Vague Age: She may be Older Than She Looks; in "The Substitute", she mentions that she has been teaching for 49 years, which may mean that if she started teaching when she was 18 to 21 years old, that would make her age about 67 or 70. In "Lost Playground", her mother, Millie Shoop, mentions that she told her to get off the playground 30 years ago.
- Voiced by: Skyler Page (season one), Donovan Patton (every episode after Page's termination)
A substitute teacher/detention handler at Aberdale Elementary.
- Abhorrent Admirer: Frequently hits on Ms. Baker.
- Butt-Monkey: He takes a lot of crap.
- Donut Mess with a Cop: His policing as revealed in "Officer Moody" consisted solely of eating donuts, and being a general doofus.
- Fat Bastard: He's heavyset and crabby.
- Fat Idiot: Fat and stupid.
- Good Is Not Nice: His grouchiness does not compare with how much he wants his students to succeed.
- Grumpy Bear: He acts like it.
- Hidden Heart of Gold: See Good Is Not Nice above.
- Jerk with a Heart of Gold: Despite his perceived grumpiness, he does care for the students, as seen in episodes like "Dream Boat" and "Freedom Cactus".
- Must Have Caffeine: Is almost never seen without a mug of coffee.
- Small Name, Big Ego: Thinks very highly of himself, despite only having been a police officer for two years.
- Took a Level in Kindness: In the first season, he was portrayed as very gruff and firm, not taking kindly to hijinks. But now, he often seems to want to get involved with the students, and can be just as silly as them.
- Voiced by: John DiMaggio
Sumo's dad. Tries his best to manage his dozen offspring.
- Ax-Crazy: He's very psychotic, at times
- Badass Mustache: His distinguishing trait.
- Big Ol' Unibrow: Type 2.
- Bumbling Dad: Not to the extent of Chad.
- Characterization Marches On: In "Dinner Party" and "Dream Boat" he's fairly mellow and adjusted. Then comes "Nothing Ventured" where he's suddenly a manic, get-rich-quick type schemer. And then he reverts back to his mellow, sensible persona afterwards.
- Cloudcuckoolander: "Nothing Ventured" shows he's almost as wacky as Sumo. When trying to build a modern art gallery with Chad, he suggests they make a "fire door" but actually means a door made of fire.
- Like Father, Like Son: He's childish and hyperactive like his son.
- Manchild: He's pretty immature and silly.
- Spell My Name with an "S": Same as Sumo, his last name varies between "Sumowski" and "Sumouski" in some episodes.
- Voiced by: Cristine Lakin
Sumo's mom and wife to Mel.
- American Accents: Her accent has a southern twang to it
- Expy: Of Nancy Gribble, as far as her appearance goes.
- Flat Character: She wasn't even a major role in any of the episodes but to be shown with her family.
- Hartman Hips: This could promptly make her the more standing out to Clarence and Jeff's moms.
- Mama Bear: This trait can be seen in most episodes featuring her.
- Ugly Guy, Hot Wife: More attractive than her husband Mel.
- Voiced by: Ari Rubin
An older brother to Sumo and all of his young brothers and sister.
- Big Brother Bully: Between him and Joseph, who's been doing it to Sumo, more than to all of their young brothers and sister.
- Dumb Muscle: His phyiscal appearance, clarifies that he's muscular, but lacks intelligent, he even failed to master nail-stumping, which Sumo seem to do it better than him.
- Dumb Blonde: A rather male derivative to this, but not simple minded like Clarence.
- Jerkass: Like this to Sumo and Clarence.
- Jerkass Has a Point: Averted, after he and Sumo got in a brawl and Sumo explained to Tanner the main reason of bullying, with Tanner explaining that he wanted Sumo to be tougher and claimed that Clarence was babying Sumo too much.
- Voiced by: Mena Suvari
- Bare Your Midriff: Is never seen without the outfit in her picture.
- Extreme Doormat: She doesn't stand up to anyone.
- Gag Nose: A pink one, it looks like her son's nose.
- Parental Obliviousness: She's unaware of her son's jerkish behavior.
- Rich Bitch: Very much a subversion. She is fairly upper-middle-class, but she's a nice, if somewhat neurotic, woman and has the same struggles with parenting as everyone else, regardless of where they are on the socioeconomic ladder.
- Stacy's Mom: Emilio thinks she's "foxy."
- Strong Family Resemblance: She looks like a feminine, skinny, adult version of her son Belson. They even have similar noses.
- EJ voiced by: Lea DelariaSue voiced by: Tig Notaro
- Blonde, Brunette, Redhead: E.J. and Sue are the brunette and redhead to Mary's blonde.
- Butch Lesbian: EJ; she dresses in a more masculine manner.
- Fat and Skinny: EJ is squarer and bigger than the skinny Sue.
- Lipstick Lesbian: Sue; she dresses in a more feminine manner.
- New-Age Retro Hippie: They both show signs of this, although Sue is the only one who dresses accordingly.
- Red Oni, Blue Oni: EJ is Red, Sue is Blue.
- Strong Family Resemblance: It's pretty obvious Jeff gets his square noggin from EJ.
- Those Two Girls: In most of their appearances, they're seen together.
- Tomboy and Girly Girl: EJ's the Tomboy who dresses in traditionally masculine attire to Sue's Girly Girl.
- Expy: Of Clarence' grandma, Dilliss, except Rosie isn't senile.
- Granny Classic: She dresses the part with muted clothing colors and a shawl.
- Prim and Proper Bun: She's just as overbearing as her grandson is, with the cube bun to match.
- Strong Family Resemblance: Like her daughter and grandson, she has a square noggin and, when she was a little girl, she looked like a female Jeff. Her personality is like his, too.
Wendle Extended Family
- Voiced by: Maria Bamford
Mary's very overbearing mother.
- Ambiguous Disorder: It's clear that she is a suffering from a form of dementia.
- Blinding Bangs: Her eyes are hidden by her hair.
- Control Freak: Dilliss thinks she needs to fix everything she sees her family doing. What's worse is that, possibly as a result of severe senility, she has no idea how to do any of these things and always makes things much worse: when she thought the knife Chad got to cut meatloaf was too sharp, she ended up stabbing him with a fork. When she thought Clarence's diorama had some pieces out of place, she completely destroys it. She thought the food in the fridge needed to be labelled, but spilled paint everywhere and took so long with it that everything spoiled.
- Killed Off for Real/Killed Offscreen: "Plane Excited" has the family going to her funeral.
- Motor Mouth: She's a super fast talker.
- Noodle Incident: It's not said how and when she died, besides that it was after Hurricane Dilliss.
- My Beloved Smother: Is this to an extreme degree in "Hurricane Dilliss".
- Scatterbrained Senior: It's implied that she's more senile than Seymour, considering that what brought her to Mary's house was her wandering away from wherever she and her husband were.
- Screw Politeness, I'm a Senior!: An elderly woman who messes up the house, among other things.
- Spell My Name with an "S": Her was name, at one point, was spelled "Dillis".
- Strong Family Resemblance: She very much resembles a shorter and older version of Mary.
- The Thing That Would Not Leave: In her first appearance, she came to visit and she took over.
- Abusive Parent: Often shown to be emotionally abusive to their son, if they're paying attention to him at all.
- Only One Name: Their last name isn't said.
- Rich Bitch: They're not that wealthy but, regardless, they're more well off and they act like they're better than everyone. Tiffany is especially this.
- Ambiguously Absent Parent: We don't know if he's divorced or if his wife passed away, though his line "Shh, let the cheeks speak to each other" leans towards the latter.
- The Lost Lenore: If Lucy (a girl he met as a kid) became his wife and passed away.
- Only Known by Their Nickname: We find out his name is "Hershel" from a flashback
- Overprotective Dad: In Lost Playground, after Camden falls and gets his cheeks deflated, he's one of the main supporters of the playground getting replaced and then later on taken down. He eventually calms down when he finds the playground equipment he used to play on with the names "Hershel and Lucy" carved on it.
- Strong Family Resemblance: Looks like a much older version of Camden
- Voiced by: Katie Crown
An overweight woman who rides around on a scooter.
- British Stuffiness: She's stuffy and has a British accent, though she might not be British.
- Catchphrase: "Harumph!"
- Charlie Brown Baldness: When her hair isn't in a bun, it looks like about a dozen hairs covering an otherwise bald scalp.
- The Dreaded: At least considered this at Mary's hair parlor.
- Early-Bird Cameo: Had a cameo in "Lost in the Supermarket" and was mentioned in "Rise 'n' Shine" long before she was the focus of an episode.
- Excessive Evil Eyeshadow: She's not conventionally evil but she's unpleasant and she wears prominent blue eyeshadow
- Fat Bastard: She's obese and unpleasant.
- It's All About Me: Carelessly ran over Kevin twice in one day and demanded that the best shampoo be used for her, using "The Customer Is Always Right" as a very cheap excuse.
- Jerkass: She's unsatisfiable, rude, and irritating.
- The Mean Brit: She's talks with a British accent and nasty.
- Too Important to Walk: In "Hairence", after Clarence dumps a huge clump of green goop on her head, it's shown she can walk just fine without her scooter.
- Unsatisfiable Customer: Used a coupon for Chuckleton's (which is a restaurant) to get a haircut. They even don't bother trying to argue that the coupon is invalid, just so they can get rid of her quicker.
- Vocal Dissonance: From her name and appearance you would think she was American, but she has a British accent.
- The Stoic: It takes a lot to faze him.
- Satellite Character: Both of her speaking roles involve interaction with Mary.