As the question has been asked:
Prodnose: humourless, reasonable oaf who interrupts the flights of fancy. (The name is journalistic slang for a sub-editor.)
Mr. Justice Cocklecarrot: well-meaning but ineffectual High Court judge, plagued by litigation involving the twelve red-bearded dwarfs.
Mrs. Justice Cocklecarrot: his wife. Very silent, until she observes that "Wivens has fallen down a manhole". An enquiry from the judge as to which Wivens that would be elicits the response "E. D. Wivens". After a worrying interval she reveals that E. D. Wivens is a cat. His Lordship observes that cats do not have initials. "This one does", says she.
Tinklebury Snapdriver and Honeygander Gooseboote: two counsel. The elbow of one has a mysterious tendency to become jammed in the jaws of the other.
Twelve red-bearded dwarfs, with a penchant for farcical litigation. Their names are Scorpion de Rooftrouser, Cleveland Zackhouse, Frums Gillygottle, Edeledel Edel, Churm Rincewind, Sophus Barkayo-Tong, Amaninter Axling, Guttergorm Guttergormpton, Badly Oronparser, Listenis Youghaupt, Molonay Tubilderborst and Farjole Merrybody.
Captain Foulenough: archetypal cad and gatecrasher who impersonates the upper class in order to wreck their social events. Educated at Narkover, a school specializing in card-playing, horse-racing and bribery.
Mountfalcon Foulenough: his priggish nephew, who brings havoc to Narkover and "makes virtue seem even more horrifying than usual".
Vita Brevis: debutante frequently plagued by, but with a certain reluctant admiration for, Captain Foulenough.
Dr. Smart-Allick: genteel, but ludicrous and criminal, headmaster of Narkover.
Miss Topsy Turvey: neighbouring headmistress, courted by Smart-Allick.
Dr. Strabismus (Whom God Preserve) of Utrecht: eccentric scientist and inventor.
Lord Shortcake: absent-minded peer obsessed by his enormous collection of goldfish.
Mrs. McGurgle: seaside landlady. Fearsomely British, until she decides to reinvent her house as "Hôtel McGurgle et de l'Univers" to attract the tourists.
Charlie Suet: disastrous civil servant.
Mimsie Slopcorner: his on-off girlfriend, an ill-informed and irritating social activist.
The Filthistan Trio: Ashura, Kazbulah and Rizamughan, three Persians from "Thurralibad", two of whom play see-saw on a plank laid across the third. They have a series of contretemps with British bureaucracy and the artistic establishment, in which the trio generally represents the voice of reason.
Dingi-Poos: the Tibetan Venus. She obtains desirable commercial contracts by using her charms to hoodwink visiting British envoys, principally Colonel Egham and Duncan Mince.
Big White Carstairs: Buchanesque Empire builder, with a tendency to mislay his dress trousers.
O. Thake: man-about-town.
Lady Cabstanleigh: Society hostess.
Stultitia: her niece, a playwright.
Boubou Flaring: glamorous but vacuous actress.
Emilia Rustiguzzi: voluminous (both in bulk and in decibels) opera singer.
Tumbelova, Serge Trouserin, Chuckusafiva: ballet dancers.
Colin Velvette: ballet impresario.
"Thunderbolt" Footle: handsome, socially celebrated boxer (who can do everything except actually fight)
The M'Babwa of M'Gonkawiwi: African chief, who occasions great administrative problems in connection with his invitation to the coronation of Queen Elizabeth II.
The Clam of Chowdah: oriental potentate
Mrs. Wretch: formerly the glamorous circus performer Miss Whackaway, now wife to Colonel Wretch and "horrible welfare worker".
Roland Milk: insipid poet