Note: This character list contain unmarked spoilers for the entire series.
Rod AllbrightMain protagonist and eldest son of the Allbright family, Rod is in the last months of sixth grade when the series starts.
- Cannot Tell a Lie: For traumatic reasons, he starts the first book pathologically honest. Frustratingly, it never works in his favor later on. He eventually overcomes this in an attempt to mislead the main villain, but even then it gets seen through immediately.
- Cassandra Truth: Despite everyone knowing he Cannot Tell a Lie, no one believes his attempts to let them know about the aliens who've landed in his house.
- Disappeared Dad: His father just up and disappeared one day, devastating the rest of the family. He spends a long time wondering why.
- Formerly Fat: He starts the first book kind of pudgy (though as he notes, the doctor told him he only needed to lose ten or fifteen pounds to be the right weight), but hard work and studying warrior science helps him get into shape by the end.
- Half-Human Hybrid: It turns out his father's disappearance is more complicated than it seemed. He is actually still fully human, but his father's side of the family is from a different sprig of the human tree...
- Humans Are Special: While we aren't noted as being particularly noteworthy among sapient species in other ways, humans are apparently nearly twice the size of most sapient life.
- Took a Level in Badass: At the start of the first book, Rod is a likable and good-hearted kid, but also kinda fat and a bit of a loser. By the end of the final book, he's a disciple of warrior science and Mentat skills, he defeats all the villain's henchmen on his own with cool-headed decision making, and he plans to return to the stars someday.
Linda and Eric AllbrightRod's fraternal twin siblings, three years old at the start of the series (Linda was born first). They started going by the nicknames "Little Thing One" and "Little Thing Two", respectively, after Rod read The Cat in the Hat to them.
- Annoying Younger Sibling: Downplayed. They sometimes get on his nerves, but he notes that they have their ups and downs. One reason he dislikes Elspeth is that she brings out the worst in them.
- Half-Human Hybrid: Much like Rod.
Jean AllbrightMother of Rod, Linda and Eric, wife of Arthur "Art" Allbright. Her father is an unnamed farmer who lives nearby.
- Glamorous Single Mother: Played with. Raising her kids for three years alone is noted to be hard on her, and the family doesn't have much money (which is a plot point when a well-heeled bully's family threatens to sue), but she is holding things together.
- Widow Woman: The disappearance of Rod's father hit her very hard. She puts on a brave face for her children, but sometimes cries in her alone time.
Arthur "Art" Allbright/Ah-rit Alber IteFather of Rod, Linda and Eric, husband of Jean Allbright. Actually a semi-alien from ancient Atlantis and founder of the Mentat under the identity "the Ferkada". He had at least one younger brother, Kah-nath. Ah-rit left Earth three years before the series began in an attempt to draw BKR away from his family, including the recently born twins, and is reunited with Rod in The Search For Snout. He finally returns home with the rest of his family at the end of Aliens Stole My Body.
- Advanced Ancient Humans: He is a scientist from Ancient Atlantis, in the modern day thanks to time dilation. And he is considered a genius even among the aliens he interacts with.
- Been There, Shaped History: Not on Earth, really, but he is the Ferkada who founded the school of the Mentats.
- Daddy Had a Good Reason for Abandoning You: Unfortunately for everyone else involved, BKR was too clever to be fully tricked, and had good reason to lie low in a galactic backwater anyway.
- Immortality Begins at 20: His biological age (as opposed to his actual age, which is measured in millenia) is elderly for a pure human. Art puts it down to a mixture of long-term suspended animation having some side effects that slow his aging, and the advanced medical science of the rest of the galaxy.
- Neuro-Vault: He has a secret that will let BKR destroy time itself, and, because he feels his own mind is not secure enough, he stashes it in his son's. This comes back to bite both of them.
- Sue Donym: Compare and contrast his "true" name and the one he was living under.
Elspeth McMastersRod's annoying younger cousin, the daughter of Jean Allbright's sister Grace and brother-in-law Roger McMasters. She comes to stay with the family for two weeks in the summer while her parents are having some trouble, and is soon caught up in Rod's adventures.
- Annoying Younger Sibling: Ticks many of the boxes, despite not technically being a younger sibling.
- Jerk with a Heart of Gold: She may be a pretty big brat, but she does care about Rod and they eventually become Fire-Forged Friends after all they go through. Rod even says in one book that she's like broccoli: you can learn to like her.
- Human Popsicle: She gets frozen into suspended animation for part of the voyage, before demonstrating her ability to be a little useful.
- Plucky Girl: Her many adventures don't traumatize her much.
BoneheadThe Allbright family dog.
Seymour and EdgarSeymour is one half of the Chibling that Rod bonded to in Dimension X, which split into a two-part creature upon reaching maturity. His most prominent feature is his head: a single enormous eyeball about the size of Rod's fist and sheathed in blue skin. Seymour's body resembles that of a "squashed, ridged, naked blue cat", but with six legs (originally four, all ending in two blobby, clawless toes), and a snaky blue neck and tail. His brain is in his torso, and he has a psychic connection to Rod's brain (a quirk of his species). He also breathes through his skin.
Edgar, the other half, still resembles their original form: a purple furball about a foot and a half long, with several pairs of legs and two large, black eyes. Except for being purple, he looks a lot like a caterpillar. Edgar does the eating for the two, beaming energy into Seymour via the latter's eye.
- Body Backup Drive: When the villains take Rod's body, Snout uses Seymour's connection to Rod to let Seymour store Rod's mind, including whatever secret is stashed there, inside portions of his own massive brain until Rod's body can be retrieved.
- Punny Name: The blue, hairless half names himself Seymour due to his being "all eye".
- Super Drowning Skills: Since Seymour breathes through his skin, he starts to suffocate once he's underwater - a fact he and Rod learn the hard way on Kryndamar.
- Vertebrate with Extra Limbs: In Aliens Stole My Body, Seymour is suddenly identified as having six legs (he only had four in The Search for Snout).
Captain GrakkerCaptain of the Ferkel, Grakker is a green-skinned humanoid from the planet Friskalama.
- Alien Lunch: He can't resist snacking on a bit of Rod's homework, much to the poor kid's consternation.
- The Comically Serious: Occasionally, his gruffness contrasts with some of the sillier situations he ends up in.
- Farm Boy: He grew up in a swamp on a "worm farm." His family was actually very successful too (he mentions being able to experience other worlds in a VR tank they owned), but he still wanted to go out and see the universe.
- Fire-Forged Friends: At school, he originally admired BKR's genius and charisma, and saw Snout as an effete loser. But, when their common discovery of BKR's cruelty united them, they became first allies, then incredibly close friends, such that they share a cabin on the ship where everyone else has their own accommodations, and their bond with one another allows Snout to track him wherever he goes.
- Jerk with a Heart of Gold: While he is a blunt, abrasive person, Rod comes to see many of his more-positive qualities and appreciate his skillful leadership across the course of the series.
- Personality Chip: Downplayed in all later installments, but "personality modules" that alter his thinking play a key part in the first book. Madame Pong switches them out from time to time. He spends most of the novel wearing a Diplomatic Module, which clashes so heavily with his natural personality that Madame Pong complains that he keeps burning them out, and proves largely-ineffective at restraining him, a Docility Module, which works too well and turns him lazy and calm even in situations where action is required, and the Berserk Module, which reduces his intelligence and leaves him using Hulk Speak but also makes him incredibly fierce and wild. The later books mention a Battle Module, which Tar Gibbons feels was poorly programmed, a Judicial Module for when he needs to discipline Elspeth after she stows away on the Ferkel in book 3, and an "Open Mind" Module.
- Top-Heavy Guy: Downplayed, but his physique is enormously muscular and powerfully built, by human standards. Rod describes him as looking like a shaved, green gorilla.
Madame PongThe ship's Diplomatic Officer.
- Cloud Cuckoolanders Minder: Played up in the first book, where she is the primary restraint on Grakker's aggression. Downplayed in all later installments, though she still takes the lead in her area of expertise.
- There Are No Therapists: Averted. She's very good at talking people through their problems.
Flinge Iblik/"Snout"The ship's Mental Officer, possessing various psychic powers. He shares a mental link with Rod, and teaches him a great deal about how to use his mind better while on Kryndamar.
- Psychic Powers: He has a whole platter of them, including telepathy and the ability to see into other planes of existence with a trance.
- Put on a Bus: Gets sucked out of dimensions and put into a coma in the second book, and the third revolves around hunting for where he ended up.
Tar GibbonsMaster of the Martial Arts and "Warrior Scientist," it takes Rod as its student in I Left My Sneakers In Dimension X.
- Bizarre Alien Biology: It doesn't correspond to any kind of human gender, enjoys the taste of paper-mache, and "grows" its own snacks that can fly and scream.
- Fantastic Honorifics: "Tar" is a title, rather than part of its name, like "doctor" or "professor." The "Tar" means, roughly, "wise and beloved warrior who could kill me with his little finger if he so wished."
- "It" Is Dehumanizing: Averted. It is neither male nor female, and thus prefers to be called by "it" than by "he" or "she". Rod points out that this is very awkward given the language they're using, and the Tar agrees, but insists that it is less offensive than calling it "he" or "she" would be.
- Nerves of Steel: Cool headed decision making in a crisis is part of the warrior science way.
- Proud Warrior Race Guy: Its "warrior science" involves training both the body and mind.
Phillogenous esk Piemondum/"Phil"The ship's science officer and chief pilot. He resembles a large sunflower and is something of a wise guy.
- Gasshole: An odd variant, as it's not played for humor. Rather, Phil sucks air into pods and then "burps" it out in a manner to approximate speech. Madame Pong comments early on that "burp" is not precisely the right word for the process, but it's the closest our language has.
- Logical Weakness: When he has to uproot himself to sneak into Rod's cell disguised as dinner, he's left mostly-paralyzed until he can be helped back into his pot.
- Plant Aliens: Phil, as said before, resembles a large sunflower. He also can't be picked up by scanners that only detect animal life.
- The Smart Guy: Since he handles engineering, navigation, and science, he's usually the one who has to fix and maintain everything on the ship.
- Super Wheelchair: Has a rocket-equipped pot for locomotion purposes.
PlinkPhil's symbiote, a small fuzzy creature who does the running and fetching for Phil. In return, he gets to eat any nuts, leaves or branches Phil is done with.
Deputy Rod AllbrightSee "Allbright family" section.
BKRLead villain of the series, he has blue skin and orange spikes for hair. He is known across the universe for his cruelty, which is the worst crime in the civilized galaxy.
- Big Bad: He's the chief villain behind everything in the series.
- Evil Cannot Comprehend Good: He admits that the only reason it took him so long to figure out the connection between Art and Rod is that he never in a million years expected the brilliant and enlightened scientist and time-traveler he knew to marry a good woman and settle down to live a happy life with a family.
- Evil Is Petty: While lying low on Earth and looking for his old partner, he takes great pleasure in simply enrolling in a local school to bully and abuse the students. Indeed, this is why his crime of cruelty is considered the most horrifying of crimes by galactic society: it has no mitigating factors.
- For the Evulz: Unlike Smorkus Flinders, he commits his crimes for the sheer sadistic pleasure of it, and there's nothing to indicate any kind of Freudian Excuse. Indeed, while both his large-scale plans would affect him the same as everyone else, he doesn't mind. Heck, in the case of his time bomb, it's a bonus: when the universe freezes, with countless numbers of people trapped in suffering, he'll be able to enjoy the most triumphant, joyful moment of his life for all eternity.
- Giggling Villain: He does laugh a lot, and Rod is horrified to notice it's about the same as the nasty cackling from when he bullied Rod in school.
- Idle Rich: It's mentioned that he was born into great wealth, when Rod assumes he became rich by stealing things. He was at some point seeking a job with the Galactic Patrol, but it's clearly fallen through.
- Mask of Sanity: He's good at pretending to be normal, when he bothers. It comes in handy both whilst infiltrating the Galactic Patrol Academy and while schmoozing to adults as a bully.
- Offscreen Villainy: He was the top student at the Academy, so much that, when Grakker and Snout realized what he was, they knew they'd never be believed. They brought all the evidence they could find before their teachers, and were disgraced. Grakker's story is cut off there, but, well... in between, "millions have wept."
- Phrase Catcher: While describing his actions, Madame Pong can only say, often, "millions have wept."
- Sadist: His schemes don't have higher goals. He causes pain simply because causing pain brings him pleasure.
- Stealth Insult: Grakker describes him as often making seemingly-friendly comments that are carefully worded to cause the listener internal turmoil, doubt, and discomfort at the Academy.
- Sue Donym: Not as much as Art, but his human alias of "Billy Becker" clearly recalls his actual name.
- Time Stands Still: His ultimate plan is to detonate a "time bomb" that will cause time to move in a tightening spiral, ultimately freezing forever in the moment of the bomb's detonation.
- When Dimensions Collide: He's planning with Smorkus Flinders to destabilize both their home dimensions by smushing them together, effectively creating permanent reality quakes in both.
Smorkus FlindersBKR's closest friend, originating from Dimension X, is known across six dimensions for his cruelty. This is why he and BKR get along so well.
- The Brute: He regularly serves as this to BKR, despite being a brilliant intellect in his own right.
- Freudian Excuse: Unlike BKR, whose sadism and cruelty are deliberately never explained, Smorkus Flinders is something of a Tragic Monster. As a victim of a rare occasion in which the events of a reality quake do not reverse themselves afterwards, he was left trapped in the form of a hideous giant, estranging him from all his friends and family.
- Genius Bruiser: He is called one of the most brilliant intellects in his entire dimension, and is also a super-strong giant.
- Large and in Charge: Rules over the other monsters of Dimension X by virtue of his incredible size.
- Tragic Monster: Smorkus Flinders is not responsible for either his hideous form or the way the world treated him. But, in his madness, he desires only to lash out at the world for wronging him.
- Unskilled, but Strong: Because of his incredible size, he never had to fight much, and is mediocre at it. But he's big enough to literally stick a human into his ear canal, and has the Super Strength to match, so it doesn't always matter.
- Woobie, Destroyer of Worlds: Smorkus Flinders was once a kind, normal man. His hideous, irreversible mutation has driven him quite mad, however, and his plans are still monstrous.
QuatA fish-like alien who spied on the heroes while on the planet Kryndamar.
- Karma Houdini: He's the only identified member of BKR's gang to avoid arrest, and was last seen flying away from Kryndamar on his ship after escaping from the heroes on that planet.
QuinceA member of the same species as Quat, he was part of BKR's crew on the Merkel and wears a special suit to keep him hydrated.
- No-Sell: When the rest of the crew is knocked out by an airborne gas, Quince is completely unaffected, which he explains as being because "That stuff doesn't work so well on someone who's breathing water."
BonzettaResembling a humanoid bulldog, she was part of BKR's crew on the Merkel.
Arly BungHead of security for the Mentat, she rebelled and joined BKR's crew on the Merkel.
MickeyRod's best friend on Earth, he has one younger sister, Markie. He's also described as one of the shortest kids in Rod's class, and also the nicest. Rod tries telling him about Grakker and his crew once, but Mickey doesn't believe him; even after he sees Grakker one time, he thinks he's just a toy, and Rod doesn't bother trying to correct him.
- Put on a Bus: His last appearance is having a short talk with Rod on the way to school in the opening of I Left My Sneakers in Dimension X, and is never seen again for the rest of the series. Justified in that summer vacation started a few weeks later, and Rod went off-planet for most of that time.
Mrs. NesbittAn older woman living near Rod's family. She has poor eyesight, and Jean Allbright spends a lot of time helping take care of her.
Mrs. MaloneyRod's sixth-grade teacher.
Arnie MarkleStudent and bully in Rod's sixth grade class, he idolized Billy Becker due to the other boy being just as bad (if not worse) as Arnie himself.
Mr. and Mrs. BeckerAndroids that BKR used as his "parents" in his disguise as Billy Becker.
Spar KellisOne of the inhabitants of the Valley of the Monsters in Dimension X, he's big, blue, incredibly fat and has three eyes, two in the normal place and one above them. He's also spying on Smorkus Flinders for the Ting Wongovia.
- Comically Small Bribe: He ultimately just asks to have a pair of shoes sized-up for his massive and sensitive feet.
- I Am A Humanitarian: He doesn't actually eat the human characters, since he's an ultimately good figure, but he can't help drooling because he finds them really, really delicious looking.
- The Mole: The Ting Wongovia's spy within Smorkus Flinders' organization.
GaluspaA shapeshifter from Dimension X, he provides aid to the crew and leads them to the Ting Wongovia.
- No-Sell: Thanks to their species having evolved shapeshifting abilities, he and all his species are now immune to the effects of Reality Quakes.
- Voluntary Shapeshifting: All of his kind are capable of this. It's an evolutionary response to one of the dangers of Dimension X - as he puts it, "When you can change your shape at will, a Reality Quake doesn't make that much difference to you."
The Ting WongoviaSnout's egg-brother, he somehow wound up in a position of leadership in Galuspa's village and aids the crew in bringing down Smorkus Flinders.
The Head CouncilLeaders of the Mentat, these thirteen disembodied brains of various sizes and colors offer the crew aid, but can do little for them.
- Brain in a Jar: All of them, who have given up the distractions of a physical body.