A caterpillar whom Anne briefly adopts for an episode.
- All Animals Are Domesticated: Averted. She's somewhat passive when in cat-insect form, but once she fully grows, she immediately returns to her feral nature.
- Ambiguous Gender: Domino doesn't have any particular characteristics that could define it as any gender. They consistently use female pronouns, though.
- Cats Are Mean: It's not an actual cat, it merely resembles one, but it plays the trope straight after metamorphosing into its true form.
- Cuteness Proximity: See the picture above, and squeal. Now see the picture below, and be prepared to run as fast as you can.
- Foreshadowing: What's the first thing Domino 2 does to Sprig? She licks him.
- Mix-and-Match Critters: Caterpillar and cat in larval form, moth and cat in adult form.
- Moth Menace: Its fully grown form is a moth, which threatens to eat the Plantar family (but not Anne).
- Names to Run Away from Really Fast: Her species' name is "Coastal Killapillar", indicating her killer nature.
- Numbered Sequel: It's right in Domino 2's name.
- Replacement Goldfish: For the original Domino, Anne's pet back on Earth.
- To Serve Man: Domino 2 eats amphibians, and grows to become a danger to every member of the Plantar family. However, its one of the few giant carnivores that doesn't try to eat Anne.Hop Pop: That's a Coastal Killapillar! They're dangerous amphibivores!
- Tuckerization: Both Dominos are named for Matt Braly's own Real Life cat, also named Domino.
- Visual Pun: Cat-erpillar, of course. She's an insect with many feline behavioral traits.
A gang of frog-eating frogs that dwell in the wilds somewhere outside Camp Phlegminton. They cover themselves in mud, attack other frogs, and eat them.
- Cannibal Clan: They eat other frogs.
- Covered in Gunge: They cake themselves in so much mud that they look like they're Muck Monsters.
- Don't Go Into the Woods: The scary story Soggy Joe tells Anne and the Plantars explicitly warns about these guys.
- Eats Babies: Hinted at, with all the "tadpole buckets◊" that Polly spots near the area where they attack the Plantars.
- Improvised Weapon: They're armed with axes, sickles, hedge clippers, and forks and knives. They also fling mud off their own bodies to extinguish torches.
- Nerd in Evil's Helmet: When their gunk is cleaned off, they look unimpressive and flee in fear.
- Weaksauce Weakness: Anything that'll clean their mud off.
An old enemy of Mrs. Croaker.
- Accidental Pervert: Croaker calls him one after he unintentionally flashes his belly at her while taking out another weapon.
- Arch-Enemy: To Mrs. Croaker. He's wanted to kill her for 30 years.
- Best Served Cold: He's trying to kill Mrs. Croaker for something that happened over 30 years ago.
- Mad Eye: His left eye is larger and has a visible red iris, which his right eye lacks, to emphasize his unhinged personality.
- Mood Ring Eyes: The pupil of his left eye notably turns red when he attempts to kill Mrs. Croaker.
- Noodle Incident: Jonah mentions how he'll be able to return to a certain guild once he finishes off Sadie.
- Old Flame: Sprig believes he is this to Mrs. Croaker, but actually he's her Arch-Enemy.
- Retired Badass: An old hermit who seems to have been an enforcer or assassin of some kind in the past.
- Weapon of Choice: Crossbow, although he carries a multitude of other weapons as well.
A cannibalistic family of horned bullfrogs who prey upon travelers looking for lodgings. Teddy and Martha are the married couple who own the Dandy Lion Inn. Jennifer and Julia are a set of sisters (it's never specified whether they're Teddy's biological sisters or Martha's) who might or might not also help run the inn... but definitely help eat its guests.
- Adjective Animal Alehouse: The bed and breakfast they run is called "Dandy Lion Inn".
- Cannibal Clan: They eat other frogs (which is Truth in Television for their species).
- Creepy Twins: Jennifer and Julia are all but stated to be twins and they definitely had a hand in eating unsuspecting guests.
- Eats Babies: They would have eaten Polly too!
- Even Evil Has Loved Ones: They're one big, happy, loving family of fellow-frog-eating psychopaths.
- Evil Old Folks: All four of them are around Hop Pop's age.
- The Family That Slays Together: They've eaten LOTS of other guests before the Plantars came.
- Faux Affably Evil: Teddy and Martha are the very picture of warmth and hospitality when welcoming guests into their inn. It's just a ruse to lure victims into their inn so they can eat them.
- Inn of No Return: Their bed and breakfast is this.
- Sapient Eat Sapient: Beside eating frogs, they were also willing to put Anne on their menu. Oddly, they don't seem to be interested in eating snails at all, keeping a whole herd of them belonging to their former victims.
- Seldom-Seen Species: One of the very few times horned frogs are featured in cartoons.
- Serial Killer: They have a stable full of snails, showing that they've been getting away with killing and eating other frogs for a long time.
- Uncertain Doom: Anne blows up their inn, and it's unclear if the family survived the explosion.
- Unholy Matrimony: Teddy and Martha, who dote on each other.
A seemingly-jolly merchant who runs a stand that sells berries and candies called "Barry's Berries," who is also secretly a magic user. Sprig and Anne get on his bad side when they accidentally bump into him while he's carrying a bunch of rare blue moon berries, which only grow once a decade.
- Bitch in Sheep's Clothing: He presents a friendly facade to the town for the sake of his business, but secretly he's petty, vengeful, unforgiving and willing to use the dark arts against people who've angered him.
- Black Magic: Barry's a magic user, who casts transformative curses on people he dislikes.
- Disproportionate Retribution: He curses Anne and Sprig because they accidentally caused him to spill the berries he was carrying.
- Evil Is Petty: Self-admitted.Barry: "I may look nice, but I'm petty and vengeful on the inside."
- Hidden Disdain Reveal: He reveals how much he actually resented being bumped into and losing his berries when Sprig, Anne, and Maddie track him down to his secret storage shed.Barry: "I played it cool and was sweet, because my image is half my business!"
- Hoist by His Own Petard: Maddie ends up defeating him by catching one of his curses, combining it with feathers from Anne and hair from Sprig, and then throwing it at him, causing him to turn into an amalgam of what he turned Anne and Sprig into.
- Shout-Out: Fittingly for a candy seller, he dresses like Willy Wonka, and his voice is inspired by Ed Wynn, much like King Candy.
- Slave to PR: He hides his darker nature behind a cheery front because his image is half his business.
- Villain with Good Publicity: Publicly, he presents an image of irrepressible cheerfulness.
The new head of the local daycare following the retirement of the Bogwaters, having converted it into a combat training camp for kids. In reality, a train robber who's been training children to rob trains for him.
- Affably Evil: He's affable enough to be the first teacher Anne honestly likes. He may have conned and backstabbed the kids to take the fall for his crimes, but he admits to himself that he genuinely liked them and that it's a shame they'll be locked up forever. He also shows remarkable grace when Anne defeats him, even if though it leads to his arrest.Polly: "Where's old "teachers stink" Anne?"
Anne: "THAT ANNE IS DEAD AND BURIED."
- Badass Teacher: True, he's teaching children to rob trains, but under the pretense of giving them proper combat training. And when push comes to shove, he is still a force to be reckoned with.
- Beard of Evil: Has a goatee, but it's revealed to be fake.
- Carpet of Virility: He has visible chest hair. Despite being a newt.
- Con Man: First he cons Hop Pop into thinking he's just the stern new head of the local daycare, then he cons Anne, Sprig and Polly into thinking he's really a Cool Teacher who wants to teach them combat to survive in the world. Turns out he's actually a thief who manipulates children into helping him with his heists then leaves them to take the fall.
- Cool Teacher: He may be a crook who betrayed the Plantars, but his lessons and advice are legitimately useful, and Anne, Sprig and Polly all come to respect him.
- Dashing Hispanic: A skilled, stylishly-dressed fighting instructor with a Spanish accent and surname. Subverted whene he turns out to be a con man, if an Affably Evil one.
- Graceful Loser: He is impressed when Anne manages to defeat him and doesn't seem to hold any ill will towards her for getting him sent to prison.
- Master Swordsman: He's a skilled duelist and Anne can't get the better of him in a straight-up fight even after being trained. She ends up defeating him by blinding him with sunlight as a distraction.
- Meaningful Name: "Triton" is an old name for newt and is still used in some languages such as Greek. "Espada" is Spanish for "sword."
- Shout-Out: Tritonio's outfit and his accent is highly reminiscent of Inigo Montoya from The Princess Bride.
- Stern Teacher: To begin with, strictly towards Anne. Though he explains to her that it's mainly because he sees potential within her to do better than she initially does, and he imagines her teachers at home are the same way. For his deceitful ways, it does change Anne's perspective towards the end.
- Wisdom from the Gutter: Tells Ann that he sees potential in her that she could eclipse him as a sword fighter, justifying why he is so hard on her. This is what gets Ann to try harder and decide she is going to give her teachers back on earth another chance.
- Worthy Opponent: He seems to view Anne as this after she defeats him and he's lead away to prison.
A mysterious frog who gives away potions he makes for free. His true form is that of a giant mushroom controlling the frog whose head he's attached to.
- Actor Allusion: Gary shares his name with one of Tony Hale's most well-known roles, Gary from Veep. Though Gary is the name of the mushroom, not the frog it's controlling, whose name is Lloyd.
- Beard of Evil: He has a small tuft of beard on his chin. Although the frog isn't evil, just mind-controlled by the mushroom.
- Fungus Humongous: The mushroom is about the same size as the frog controlled by it.
- Glowing Eyes of Doom: He has purple, glowing eyes, showing that he's under the mushroom's control.
- Just Desserts: He and his spores end up getting eaten by Bessie, since mushrooms are her favorite treats.
- Last of His Kind: Gary pleads that Hop Pop not feed him to Bessie since he's the last of his kind and his species will die out. Since Gary had just tried to mentally enslave everyone in Wartwood, Hop Pop's okay with that. Though the end shows that Gary's kind might not be gone for good.
- May Contain Evil: Gary's potion contains mind control spores.
- Mind-Control Eyes: Everyone infected by the mushroom gets purple, glowing eyes.
- My Eyes Are Up Here: A rare non-sexual, male example. He says this nearly verbatim to Hop Pop when he reveals his true form to get him to pay attention to the mushroom, not the frog he's controlling when he talks.Gary: "Also, eyes up here, buddy." (points towards the mushroom)
Hop Pop: "Oh, uh, sorry. It's just, you're glowing, he's got the mouth—"
Gary: "I know, right? It's totally weird. I completely get it."
- Portmanteau: Apothecary Gary tells Hop Pop that he's also welcome to call him "Apothegary."
- Puppeteer Parasite: "Gary" is the mushroom atop the frog's head. The frog that Gary has been controlling is actually named Lloyd.