Tropes shared by all of the main characters.
- Hand Puppet: Every character is a literal bare-hand puppet.
- Letter Motif: Everyone in Oobi's family has an 'oo' sound in their name: Oobi, Uma, and Grampu.
- Limited Social Circle: The shorts and most season one episodes only feature the four main characters.
- Power Trio: The three main kids make up one.
- So Last Season: The eye pieces and accessories for Oobi, Uma, and Kako were updated for every season.
- Third-Person Person: Everyone on the show refers to themselves in the third-person, due to the somewhat controversial decision to make all of the puppets speak in uber-simplified sentences. For example, "Uma, school, first day" is said in place of "It's my first day of school."
The main character. He is a curious, studious, and motivated school-age hand puppet. He's always willing to try new things or take risks, but can get bashful at times. Unlike most of the other puppets, Oobi has no accessories aside from his iconic pair of acrylic eyes.
- Aside Glance: He does this several times throughout the show, most notably in "Neighborhood!" when he glances toward the viewer as Uma kisses Kako.
- Berserk Button: He is known for being understanding, kind, and soft-spoken...unless you touch his toy car, in which case he goes ballistic.
- Big Brother Instinct: He can get very protective of Uma.
- Character Title
- Cheerful Child
- Famed in Story: He's somewhat of a local celebrity in town.
- Interactive Narrator: He talks to the viewer at least twice each episode, and usually asks the audience to join in whatever he's doing.
- Invisible Parents: Oobi and Uma's parents are never shown or mentioned at all on the show.
- Joins to Fit In: He does this in "Frieda Friend!"
- The Leader: Of the kids.
- Meaningful Name: The two O's in his name are meant to invoke the look of two googly eyes.
- Nice Guy
- Only Sane Man: Often takes this role in stories focusing on the three kids.
- Out of Focus: Many later episodes place Uma in the starring role rather than Oobi. The most prominent examples are "Uma Dreams!" and "Uma Preschool!" from season two. In both episodes, Oobi only shows up briefly at the beginning and at the end to give his signature "Oobi, you, friends!
- Salt and Pepper: He and Kako are this.
- Sensitive Guy and Manly Man: The sensitive guy to Kako's manly man.
- Trademark Favorite Food: He loves "Toasty Chunks", a fake brand of cereal.
- Vague Age: To anyone who has never read an official plot summary for the show (most of them describe Oobi as a four-year-old). Word of God says both Oobi and Kako are four, but they act a little older and sure as hell don't sound that young.
- Vocal Evolution: In the early shorts, his voice is quieter and somewhat raspy compared to his more energetic voice in the later episodes.
- Younger Than They Look: He and Kako sound and act much older than they supposedly are.
Oobis outgoing and overdramatic younger sister who looks up to him as a role model. She wears a barrette on her pinky. She never goes anywhere without Oobi or Grampu, and has trouble adjusting to situations when they aren't around. Uma has a peculiar obsession with chickens and loves to learn new words, although she always mispronounces them.
- Annoying Younger Sibling: Uma's overdramatic nature can be a lot for Oobi to handle. He never shows any signs of annoyance towards her, however.
- Bald Woman: She has no hair, being a hand. She is shown to be very proud of her baldness in "Video!" where she introduces herself as bald and turns around to show her bald head (wrist) to the camera.
- She's also notably the only female character without a wig of some kind.
- Characterization Marches On: She started out as a fairly generic baby in the shorts, but Stephanie D'Abruzzo played the role in an unexpectedly goofy and melodramatic way (relatable, too, for anyone with younger siblings) that she became a very frequent spotlight stealer.
- Comical Overreacting: She overreacts to pretty much everything.Stephanie D'Abruzzo, about Uma: "I wish I had the rights to the character, as I would love to do little videos with her where she gets frustrated by the world around her. I want to see her just try to open a sugar packet for two minutes, then end with her in a spotlight singing Sondheim's Losing My Mind."
- Companion Cube: Her doll.
- The Ditz: Delves into Cloudcuckoolander territory frequently.
- Parrot Exposition: Whenever Oobi teaches Uma a new word, she tends to repeat it. A lot.
- Precocious Crush: Has a very obvious one on Kako. She even kisses him in "Neighborhood! three times.
- Running Gag: Her love of chickens (the animal, not food).
- The Smurfette Principle: Among the main cast, Uma is the only female, but the supporting cast is almost all female (save for Angus, Papu, and Maestru).
- Tertiary Sexual Characteristics: She wears a barrette (pink ring) to differentiate her from Oobi.
- Tomboy and Girly Girl: Uma and her best friend Moppie. "Uma Preschool!" even features Moppie pretending to be a princess and Uma pretending to be a king.
Oobi's goofy best friend who is known for his big ego and constant wisecracks. Although he usually acts eccentric and carefree, he cares deeply for his friends and will often display moments of profound wisdom. He wears a red beanie cap on his knuckles.
- Ambiguously Brown: It's unclear whether he's black or Mexican, since his parents have rather dark skin tones but Kako himself has lighter skin and frequently uses Spanish phrases.
- Attention Deficit... Ooh, Shiny!: He's distracted a lot.
- Big Eater: He loves cake. A gag in "Uma's Birthday!" shows him eating all of Uma's leftover birthday cake and eventually passing out from having so much.
- Black Best Friend: Assuming he is black, anyway.
- Catchphrase: "Perfecto!"
- Disguised in Drag: His costumes and personas in "Neighborhood!" are all female.
- The Ditz: Not so much as Uma, but he is still ditzy.
- Nice Hat: His red cap.
- Oblivious to Love: He seems to be unaware of Uma's Precocious Crush on him.
- Salt and Pepper: He and Oobi.
- Sensitive Guy and Manly Man: The manly man to Oobi's sensitive guy.
- Talkative Loon: He can be a real chatterbox.
- Trademark Favorite Food: Cake.
- Vague Age: Like Oobi, his age is very unclear as he sounds and behaves much older than four (the age given for Oobi in official plot summaries).
Oobi and Uma's clever, lively, and somewhat hapless grandfather. He takes care of the kids and always has some words of advice for them. No mention is ever made of Grampu's children or children-in-law (Oobi's presumed parents), as the intention was to have the show's main family represent a nontraditional family unit.
- Absentee Actor: "Frieda Friend!" is the only full-length episode where he doesn't make an appearance.
- Butt-Monkey: The kids' mischief almost always results in some kind of comical mishap for Grampu.
- Bumbling Dad: Certainly qualifies, despite being a grandfather.
- Chick Magnet: As a running gag, all of the lady hands in town are shown to know Grampu well and even flirt with him, too. Most notably his girlfriend Inka and Bella, the supermarket owner. In the "Theater!" episode, he's the only male in the audience, and all of the girls flock around him and offer him snacks.
- Cool Old Guy: To the kids.
- DecemberDecember Romance: He is in a romantic relationship with Inka, Oobis elderly piano instructor.
- Grandparental Obliviousness: Averted with Grampu, as he is very much involved in the kids' lives.
- Never Say "Die": Considering all of the possibilities (like him being involved with Inka), it would make sense if Grampu's former wife (Grammu?) passed away before the events of the series. This is never actually stated outright.
- Non-Standard Character Design: Tyler Bunch never shaved his arm so that Grampu would have arm hair and resemble a grandfather hand. This decision was made during production of the original shorts, which only featured the four main characters. More adult characters were added in the full-length episodes, but none of them have arm hair, making Grampu stand out.
- No Peripheral Vision: Grampu never thinks to look upwards in "Make Pizza!" when the pizza dough clings to the ceiling and later falls down, covering him.
- Parental Substitute: The show wouldn't change at all if Grampu was just referred to as the kids' father.
- Signature Laugh: He has a distinct chuckle.
- Unnamed Parent: Assuming Grampu isn't his real name.
A very close friend of Oobi who just happens to be a foot puppet instead of a hand. She cant always play the same games as Oobi due to her completely different appearance and lifestyle, but this doesn't stop them from finding ways to play together.
- Alliterative Name: Frieda the Foot.
- Fantastic Racism: Being a foot, she is meant to represent a person of a different race or background from the hand puppet stars.Tom Ascheim of Sesame Workshop, about Frieda: "We have to keep things really simple, and this was a way to communicate the idea that difference is good."
- Implied Love Interest: The way Oobi acts around Frieda certainly seems to imply he has a crush on her, but because the show's target audience is young kids, it's never stated outright.
- Love at First Sight: Just when he sees Frieda for the first time in "New Friend!", Oobi is instantly compelled to meet her. He then spends the entire episode trying to figure out some way they can both play a game.
- No Mouth: Being a foot, she has no mouth and moves her toes when she talks.
- Ship Tease: With Oobi. The episode "Frieda Friend!" shows that Oobi will go to great lengths just to fit in with Frieda's group of friends, and that he gets disappointed when he can't spend time with her.
- Species Surname: Although it's not entirely clear whether "Foot" is her last name or just a title.
- Twice Shy: In Frieda's debut episode, both she and Oobi are very hesitant to talk to each other, despite both wanting to play together. At first, they spend more time looking around awkwardly than actually talking. Eventually Grampu helps get them acquainted with each other and they make up a game, "kick catch," which becomes a recurring pastime for them.
Oobi and Angus's piano teacher. She develops a romantic relationship with Grampu throughout the series and becomes his girlfriend in the later episodes. She has an ambiguous European accent and always wears lots of jewelry.
- Elderly Blue-Haired Lady: She has purple hair, a variant.
- Funny Foreigner: Inka's accent and love for French cuisine are often used for comedy.
- Love at First Sight: Grampu falls for Inka as soon as he first sees her.
- The Storyteller: She tends to talk a lot with Grampu about her experiences in France.
- Vocal Evolution: Her accent became less exaggerated as the series went on, probably to make her easier to understand.
- What the Hell Is That Accent?: Inka speaks with an interesting German-meets-French accent.
Oobi's good friend and fellow piano student. He is nerdy and talks with a high-pitched, nasal voice. He is perpetually nervous but has a true talent for singing and performing on stage.
- Early-Bird Cameo: He first appeared in the opening theme for season two before his official debut in the "Halloween!" episode.
- Hidden Depths: Despite his nervous demeanor and nasally voice, he is a great actor and musician.
- Nonstandard Character Design: His design is unique among the characters as his eyes are below his fingers, rather than above them.