Toward the end of Black Panther, a group loyal to the recently overthrown T’Challa climbs the mountains of Wakanda and pays a visit to M’Baku, the leader of the Jabari tribe. First, T’Challa’s mother, Queen Ramonda (Angela Bassett), ex Nakia (Lupita Nyong’o), and sister Shuri (Letitia Wright) plead for M’Baku’s help in reclaiming the throne. M’Baku, played by the relatively unknown Winston Duke, is unmoved but respectful. Suddenly, the unthinkable happens: A (white) CIA agent named Everett Ross (Martin Freeman) chimes in. M’Baku balks.

And then, in one of the film’s most viscerally satisfying sequences, he barks. And barks. And keeps barking.The scene continues well past the initial moment of vindication, and it just feels good, especially as a reprieve from the attempted-regicide-focused plotline that it interrupts. M’Baku barks not just with annoyance, but with disgust, as his tribesmen join in with him. Where most of Black Panther’s male characters regard Ross with curiosity if not appreciation, M’Baku cannot be bothered. As M’Baku, Duke gently contorts his face into an avatar of disdain, conveying (black) audiences’ irritation with this fly-in-the-ointment-ass federal officer.

“If you say one more word, I’ll feed you to my children!” M’Baku bellows.

When Ross immediately clams up and looks visibly shaken, M’Baku laughs. “I’m kidding. We’re vegetarians.”

Duke extends his laugh with a knowing humor; it echoes throughout the throne room. He is commanding, unnerving, and … somehow also adorable, giggling to himself with all the abandon of a substitute teacher who’s just made an accidental pun.

Winston Duke is Black Panther’s biggest surprise.

Where M’Baku easily could have become a hypermasculine character relegated to the margins of fight scenes and one-dimensional villainy, Duke’s sly charm paints a far more complex emotional landscape. It is no surprise, then, when the film reveals that M’Baku and his people saved T’Challa and have been keeping him alive. When T’Challa is revived, the two share a solemn, gentle dialogue; M’Baku rebukes T’Challa for the monarchy’s past neglect of the Jabari tribe, an admonition laced with anger but rooted in quiet disappointment. Their conversation ends with the Jabari leader refusing to “[sacrifice] Jabari lives” to help T’Challa reclaim the throne.

Duke’s performance makes it clear M’Baku’s stubbornness is rooted in concern for his tribe. Where Erik Killmonger seeks only vengeance on his bloodlust-fueled rampage, M’Baku’s reasons for desiring the Wakandan throne encompass multitudes. That many of these scenes take place within the confines of his mountainside lair in Jabari Land only heightens the catharsis of both M’Baku’s throaty admonition and his commitment to protecting his people; it’s the only part of the film spent focused on M’Baku’s territory.

no offense but my vegetarian mans m'baku had greater character development in a single movie than most mcu characters did in trilogies pic.twitter.com/PYgrFfsgg2 — shine || BP OUTSOLD (@vvakandha) February 17, 2018

The Ryan Coogler–directed film boasts no shortage of Hollywood heavy hitters. The titular role is played by biopic/superhero titan Chadwick Boseman; frequent Coogler collaborator Michael B. Jordan takes on the villainous Killmonger; Nyong’o plays loyal humanitarian Nakia; Danai Gurira leads the Dora Milaje as the fierce Okoye, with Daniel Kaluuya playing her lover W’Kabi; Bassett, Forest Whitaker, and Sterling K. Brown round out a cast culled from black Hollywood’s elite. But amid the star-studded ensemble, the relatively unknown Duke breathes life into the role of M’Baku. One of the comic’s lesser villains, M’Baku first appears in the film during King T’Challa’s coronation ceremony. Imposing and impatient, he insists on challenging T’Challa, the latest successor in a line of kings who have ignored the needs (and existence) of the Jabari tribe. The resulting struggle is one of the first moments we see T’Challa falter; he is almost no match for M’Baku’s Herculean strength. But T’Challa eventually gains control over his much larger foe with a dubious leg lock, and M’Baku cedes the challenge in a moment of quiet, vulnerable strength. Duke imbues the rugged leader’s surrender with both irritation and grace; when the Jabaris retreat, he remains forceful even in defeat.

Though M’Baku technically isn’t new to the Marvel universe, Duke grants the relatively minor character outsized dimension. Black Panther, a superhero film, features no shortage of intense fight scenes and conflicts over the future of the (semi-)free world. As M’Baku, Duke excels at interrupting these fraught moments with both quiet dignity and unexpected humor.

Where Boseman’s T’Challa is often reserved and Jordan’s Killmonger reactionary, Duke’s M’Baku is both steadfast and cooperative. The actor brings an undeniable dynamism to the comparatively small role, an unexpected treat in a film packed to the gills with talent. The Marvel Cinematic Universe is bloated with star power; for every newcomer to the scene, the studio relies on 10 established industry darlings. Duke, a Yale graduate with roots in Tobago, shakes up both Black Panther and the MCU (alongside Wright). His costars have decorated résumés spanning decades; Duke was in seven episodes of Person of Interest. Still, he offers Black Panther and the MCU a foreboding presence, a robust physique, and a surprisingly warm heart.

It may not have been expected, but it’s certainly welcome. There’s no question who(se arms) I’ll be keeping an eye on during Avengers: Infinity War.