When Arthur is on his food-gathering expedition early in the book, he accidentally makes too much noise inside a greenhouse. This draws its occupants out to investigate, including "a very large lady with a very long stick" (1.22), who shouts at Arthur: "'You little varmint! Come down here and give me back my bananas!'" (1.23). She whacks at him with a stick, connecting with his wings. While Arthur does manage to get away, we shudder to think what she would've done to him if she'd caught him. This lady sure seems overprotective of her bananas.
Heck, you might even say she is bananas.
Bert is a rat who wears a beret and records everything that happens to him in a notebook. This is rather handy when the captain of the Nautical Laundry asks him to give an account of mysterious activities in the supposedly abandoned Cheese Hall.
Deep underground, there's a colony of cabbageheads—some old, some young, some captured by Snatcher, some not. One of the older cabbageheads gives the queen advice on how to speak so that her subjects can understand her, while some of the younger cabbageheads volunteer to go forth and find the aboveground cabbageheads to keep them posted on where the colony must relocate.
What we see of various cabbageheads confirms that they're a timid group. Some of them venture out as a delegation to ask the boxtrolls to fix the underground hydration system, but they're captured in a net. They spend a lot of time "trembling" in the trap (17.7), and when some men appear to take them aboveground, "The cabbageheads trembled even harder" (17.8). Poor things.
Coco is one of the rabbit women who meet a disguised Willbury and their party at an entrance to the underworld. She wears a suit of brown rabbit fur, and her companion, Fen, wears a suit of gray rabbit fur. They agree to guide the "boxtrolls" through their tunnels, but only if everyone is careful. The rabbit women lead secluded lives that are mysterious to everyone else since they're rarely seen.
The women tend underground gardens, spin, weave, and read books aloud. As Fen explains, "'We are very fond of books. You can learn nearly everything from them that rabbits can't teach you'" (36.36). Literate rabbit-lovers… Sure, why not?
According to Willbury, "'they were abandoned babies or little girls who fell down rabbit holes. The rabbits took them in and brought them up as their own… as they grew up, they took charge and now look after the rabbits'" (36.33). It occurs to us that the idea of girls falling down rabbit holes might be a sly nod in the direction of Alice in Wonderland, but what do you think?
This group of "very shifty-looking men" (14.40) stand outside the Patent Hall trying to con inventors into signing away the rights to their original inventions. Willbury takes offense at their existence, describing them as "'the very scum of the mechanical world. Technical vultures!'" (14.43). They slyly pressure down-on-their-luck inventors to sign over the patent rights to their machines, and thus turn a profit.
Indeed, Willbury's presence frightens them, probably because before retirement he made it a point to persecute them. They're scared to the point where after spotting him, they "were now trying either to hide behind the tents or slide along the walls and out the exit" (14.46). If they're half as bad as Willbury describes them, then good riddance.
This lady arrives in Ratbridge around the end of the story. When some of Ratbridge's fashionistas approach her, she reveals that they've been lied to: hexagonal buttocks are not, and never have been, in fashion. Thanks for the tip, lady.
This is a "friendly looking rat" (16.27) who works aboard the Ratbridge Nautical Laundry. He's in charge of collecting laundry and dividing it into color-safe piles. He leads Arthur, Willbury, and Marjorie to the captain when they first arrive on the ship, and he also contributes his perspective on Framley's disappearance, saying that he'd gotten in a fight with Framley the day Snatcher visited the ship, and that Snatcher had watched the fight and talked to Framley afterward.
This is one of Ratbridge's fashionistas. She tries to connect with a Frenchwoman who recently moved to Ratbridge about Parisian trends, but is so shocked to hear that Madame Froufrou lied to them that she "dropped her pet boxtroll and fainted" (55.23). Whoops. At any rate, she spearheads the group of fashionable ladies that insist that Marjorie take the size out of their behinds, which solves the problem of how to resize all the underlings and Marjorie herself. Yay.
These two rats disappeared from the Ratbridge Nautical Laundry, leaving the rest of the crew concerned because "They were really good blokes" (15.53); plus one of them was the captain's brother, too. Turns out that Snatcher abducted them so he could try out his resizing machine on them. Thanks to Arthur, though, they make it out of the Cheese Hall before everything explodes, and they're eventually returned to their normal size.
The female ruler of the cabbageheads has an extensive vocabulary, which would be just fine except it seems like her subjects can't even understand her. For instance, she says stuff like:
"Pursuant to the ever-rising levels of ill, commodious ablative liquids, we believe sustainable brassica production fails to be feasible." (29.2)
Um, say what? This lady could give Willbury a run for his money.
Luckily, though, one of her subjects reins her in, and even though she seems embarrassed to need the correction, she eventually relays her message in plain language. It seems like a good thing if your royalty is willing to take input from commoners, just saying.
These probably aren't their real names, since Madame Froufrou (Snatcher in a dress) introduces them as "'my French fashion specialists'" (13.53). Further, they don't look very fashionable, as they're dressed in "dirty pink suits" (13.52). They're probably just some of Snatcher's goons who had the poor fortune of having to accompany him on a fashion mission that day.
Way back when, Snatcher was playing a game of cards at the Nag's Head Inn. His opponent was a "red-faced man" (39.38) who accused him of cheating by saying, "'It is not possible to have a hand of cards containing seven aces!'" (39.38). Truer words have never been spoken, and clearly this guy knows his math. Unfortunately, his confrontation led to Snatcher poisoning him with Oil of Brussels. The poison knocked him out, and it took him a long time to recover, plus he lost his memory. Bummer.
When Willbury, Marjorie, and the crew of the ship are disguised as boxtrolls and trying to get out of Ratbridge, two town guards come strolling along. Their first thought is to try to steal what's in the boxes, reasoning that "'You must expect natural wastage when you leave something lying about, don't you think?'" (35.17). These guards obviously do not suffer from having a strong moral compass.
When the boxes come alive and are revealed to be boxtrolls, "The two guards looked round and fainted at the sight of a cartload of boxes all standing up at the same time" (35.24). Ha—serves 'em right.
Described as "rare" (21.3), this critter is in the dungeon under the Cheese Hall when Arthur comes in looking for his friends. It must, indeed, be lonely, since when Arthur frees all the critters and they go back to the ship, it runs "in the opposite direction, looking miserable" (26.43). Poor thing.