Mark Williams as Billy the Goat in Stardust (2007)

Among the witches, pirates and squabbling princes of Stardust (2007), one of the funniest turns is also one of the smallest. Mark Williams plays Billy, a goat who has been turned into a human being. Fans who say the part looks written for him are describing a rare case where a character’s whole joke depends on an actor’s comic instincts.

Billy belongs to the film’s wilder corners, where magic is both dangerous and faintly ridiculous. For viewers who know Williams as Arthur Weasley in the Harry Potter films or as a veteran of British sketch comedy, the casting makes immediate sense.

The film around the goat

Matthew Vaughn directed Stardust from a screenplay by Jane Goldman and Vaughn, adapting Neil Gaiman’s novel. In Roger Ebert’s account, England is divided from the fantasy kingdom of Stormhold by a wall. In the village of Wall, a young man named Tristan (Charlie Cox) promises to fetch a fallen star for the girl he loves. The star turns out to be a woman, Yvaine (Claire Danes). Witches led by Lamia (Michelle Pfeiffer) and the sons of the dying King of Stormhold (Peter O’Toole) are hunting her, and Ian McKellen narrates.

It is a crowded cast, and the film runs on supporting turns. Ebert, reviewing it on August 9, 2007, enjoyed it but found it cluttered. He singled out Robert De Niro’s sky-pirate Captain Shakespeare as its most entertaining element. Billy sits in that same tradition of small, vivid comic parts, in a film Ebert said played more like a series of vaudeville acts than a single tidy plot.

What the part asked of Williams

A man who used to be a goat is an easy gag to overplay. The role asks for a performer who can make the premise funny by treating it seriously. That is the register Williams built his name on, deadpan, unfussy and a little put-upon, and it fits a character who must make sense of a body he did not choose.

The part calls for quick, character-driven comedy rather than speeches. In a fantasy that otherwise leans on romance, swordplay and star turns, a performer who earns a laugh in a few moments is valuable. That is the job Billy does, and it is why viewers remember him long after the plot details fade.

Where it sat in Williams’s career

By 2007 Williams was already well known on British television. He wrote and starred in The Fast Show, the sketch series for which he is best known in the UK. His film work had reached a worldwide audience through the Harry Potter series, where he played Arthur Weasley. Harry Potter and the Order of the Phoenix was also released in 2007, so that year placed him in two large fantasy franchises at once, one as a family man and the other as a goat.

The two roles show his range within a single genre. Arthur Weasley is warm, flustered and fond of Muggle gadgets. Billy is a comic oddity in a fairy tale built to be silly. Neither is a lead, but both are the kind of supporting performance that audiences recall with affection.

What came after

Williams has kept working across screen and voice roles. He voiced Barry in the stop-motion comedy Early Man (2018). Since 2013 he has played the title role in the BBC’s Father Brown, the cozy mystery loosely based on G. K. Chesterton’s stories. The thirteenth series returned to BBC One and iPlayer on January 9, 2026. It sent the Kembleford cast to the seaside for the first time, filming at Weston-super-Mare. Teasing the run, Williams promised “kidnappings, murder, madness and mirth”.

FAQ

Who does Mark Williams play in Stardust?

He plays Billy, a goat who is transformed into a human being. He is part of a large ensemble that also includes Charlie Cox, Claire Danes, Michelle Pfeiffer, Robert De Niro and Peter O’Toole.

Who directed Stardust and where does the story come from?

Matthew Vaughn directed it. He wrote the screenplay with Jane Goldman, adapting Neil Gaiman’s novel of the same name.

Is Mark Williams still acting?

Yes. He is still playing Father Brown for the BBC, with the thirteenth series having aired from January 9, 2026. He was born on August 22, 1959, in Bromsgrove, Worcestershire.

Header photo: Raboe001 / Wikimedia Commons / CC BY-SA 3.0, modified: resized and blended with an AI-generated background. The person in the header is a real photo; only the background is AI-generated.