Amos Diggory (Jeff Rawle)
Cedric Diggory’s (Robert Pattinson) dad is played by legendary sad sack actor Jeff Rawle (you might know him as George from late, lamented TV news sitcom Drop The Dead Donkey).
He’s portrayed initially as a much more enthusiastic and proud father, but he also prompts one of the more emotional moments in the series when the Gryffindor champion is killed at the end of Goblet.
For that reason alone he deserves to make our list…
Lee Jordan (Luke Youngblood)
Motor-mouthed Quidditch commentator Lee is a staunch Gryffindor man, cheerleading for its team even as he’s supposed to be providing objective narration of the game.
His over-enthusiastic prattle about Potter puts off Harry slightly during his first big game, but our hero overcomes the problem.
We’d like to see The Deathly Hallows bring him back (he’s been MIA since Chamber Of Secrets) to run his Potter-supporting pirate radio station.
Colin Creevey (Hugh Mitchell)
Every boy-with-a-destiny needs a hero worshipper. And Colin is the lad to worship Harry until Potter is heartily sick of him.
Fizzing like space dust sweets, Colin is constantly snapping pics of Harry, and insists on trailing him with all the gusto of a small puppy.
Eventually, Colin becomes a little bit more useful, joining Dumbledore’s Army and helping in the Battle Of Hogwarts.
Spoiler Alert! It doesn’t go so well for poor Colin. So let's remember him as he was: slightly annoying, but brilliant all the same.
Madame Rosmerta (Julie Christie)
Largely relegated to colour scenery (despite being played by the still-glamorous Julie Christie), Rosmerta is the landlady of The Three Broomsticks in Hogsmeade.
When she’s not stirring up teenage hormones in Prisoner Of Azkaban, she’s serving Butterbeer and moaning that the Dementors’ arrival is driving away her regular clientele.
In Half-Blood Prince, she is used as a pawn of Voldemort, but Christie’s name is not listed on the cast, so if she’s in it, they’re keeping that quiet. Fingers crossed…
Aragog (voiced by Julian Glover)
Hagrid’s giant spider (he raised him from birth... awwwww), this dangerous beastie lives in the Forbidden Forest with his missus, Mosag and their several thousand spider-kids.
He’s generally unfriendly to anyone but the lumbering giant and threatens to snack on Harry and Ron until they reveal that they’re friends of Hagrid.
Aragog provides much needed info on the “monster of the chamber” in Secrets and nearly scares Ron to death. If only he’d succeeded…
Professor Pomona Sprout (Miriam Margoyles)
Poor old Professor Sprout gets short shrift in the film series compared to the books – she’s just one of the casualties of the movies’ need to trim the plots to running time.
But she plays a key part in Chamber Of Secrets at least, putting her Herbology skills to good use by treating those affected by the Basilisk’s petrifying gaze.
She’s played in the films by Miriam Margoyles, who we wish got more to do. She’s apparently cropping up again in the Deathly Hallows adaptation, so perhaps this plant obsessive will get another moment in the sun.
Frank Bryce (Eric Sykes)
Isolated World War II veteran Bryce lives on the grounds of the Riddle Estate, and generally watches over the place.
He has a long, complicated history with the family (he was accused of their murder at one point, thanks to Tom Riddle’s magic schemes) – though none of that is explored in real detail in Goblet Of Fire.
Still, his careworn, elderly presence helps kick off Goblet when he’s unceremoniously murderlised by Wormtail and Voldemort.
Nearly Headless Nick (John Cleese)
Or, to give him his full name, Sir Nicholas de Mimsy-Porpington.
He’s the Gryffindor house ghost who crops up briefly in The Philosopher’s Stone and again in Chamber Of Secrets, though like many other minor characters, he has a lot more to do in the books.
Nick helps establish the flavour of Hogwarts for Harry; letting him accept the fact that paintings move and spirits float about the place.
He’s also one of the characters attacked by the Basilisk in Chamber, leading Harry to gear up for his big confrontation in the film.
Stan Shunpike (Lee Ingleby)
The conductor of the magically powered Knight Bus, Stan is the cocker-nee, cock-sure lad who must help Harry get from Little Whinging to The Leaky Cauldron, where he has to face the Minister Of Magic about casting a spell in front of muggles.
He’s also a useful source of info – his paper includes plenty of exposition about Sirius Black’s escape from Azkaban in the third film.
Also on the bus? Driver Ernie Prang, who gets one or two lines in the book (“Arr”) and zero in the film. Oh, and a severed head voiced by Lenny Henry.
You don’t get those on yer bendy buses, do you?
Aunt Marge (Pam Ferris)
Roly-poly annoyance Marge is the sister of Uncle Vernon (Richard Griffiths), and proves to be just as stupid, bloated and ignorant as the rest of her family.
Despite her small screen time, she plays a pivotal role in Prisoner Of Azkaban as she insults Harry’s dead parents, causing him to turn her into a human balloon and face expulsion from Hogwarts for using magic in front of muggles while being underage.
Plus, his revenge is poetic justice. And they say good things only come in small packages…