Who could Matthew Rhys voice in Invincible season 4? Key characters explained

Matthew Rhys, most known for The Americans, Perry Mason and voicing Emperor Belos in The Owl House, was briefly revealed among the cast in the renewal video, sparking debate over just which character the Welsh actor has voiced in the upcoming seasons.

With Mark (Steven Yeun) and Oliver Grayson (Christian Convery) set to join their father Nolan (JK Simmons), Allen (Seth Rogen) and the Coalition of Planets in the upcoming showdown with the Viltrumites, there’s certainly plenty of key characters yet to make their appearance in the show.

Read on to find out more about the key characters that the Welsh actor could be voicing in Invincible season 4.

General Thragg (the most obvious suspect)

With a certain supreme overlord of the Viltrumites set to make his long-awaited debut in the fourth season, many fans have instantly connected the announcement of the Perry Mason star to the deadly Thragg - and for good reason.

The arrival of Conquest on Earth has certainly paved the way for the Grand Regent, with season 4 promising appearances from two of the deadliest villains from Kirkman’s comic book series.

The brutal leader is the ultimate warrior and the strongest of the (dwindling) pure-blooded Viltrumites, and is hell-bent on restoring the empire to their former glory.

The major antagonist has a huge role to play in the looming Viltrumite war, with the defeat of Conquest by the Graysons and their allies making them prime targets for Thragg and his army.

But how likely is it that Matthew Rhys will voice the Viltrumite leader? Well, the Welsh actor has certainly earned plaudits for his voice work as the main villain for The Owl House, and the character certainly shares a lot of similar traits to Thragg.

Rhys also has plenty of experience in voice acting - significantly more than the major cast - so despite not being as well known as newcomers Jeffrey Dean Morgan or Jonathan Banks (with the latter only making a brief cameo), he could definitely bring the fearful command and intensity of Thragg to the screen.

Space Racer (another likely candidate)

Another character set to play a major role in the looming conflict has already been quietly introduced in the show. Remember those sci-fi novels which Nolan published? Well, the books include key information to help bring down the Viltrumites, with Space Racer proving a key part.

Over 100 years ago, Nolan overpowered and buried the alien known as Space Racer, as he proved a major threat to the Viltrumites as he wielded an incredibly powerful gun which fired indestructible blasts.

However, with Nolan and Allen setting out on a mission to recruit allies for the Coalition of Planets against the Viltrumites, Nolan will undoubtedly need the gun - and its owner - to join their cause.

While Rhys is potentially more suited to the villainous Thragg, Kirkman and co generally tend to cast bigger names for their major characters - and there’s none more anticipated than the Viltrumite leader. Therefore, Space Racer is more of a safe bet.

Dinosaurus (a possible contender)

Dinosaurus, aka David Anders, is another fan-favourite character who is yet to be introduced in the series, but has a major impact on Mark Grayson and his outlook on superheroism.

The character is an antagonist in the comics, with the highly intelligent superhuman dinosaur possessing hugely destructive powers and immense strength. Think the Incredible Hulk with jaws!

While his extremist actions and views often see him coming to blows with Mark and the Guardians of the Globe, Dinosaurus does play an integral role in the upcoming Viltrumite conflict, surprisingly aiding Mark.

This intriguing foe-turned-friend provides a fascinating delve into the morally greyer areas of superheroism, and Matthew Rhys's experience in the dark legal drama Perry Mason could certainly be a perfect fit for the role.

If Robert Kirkman and co follow a similar suit to previous seasons in regards to casting, we’ll have to wait until season 4 debuts to find out just who is voicing the major players. Roll on 2026!

Invincible season 3 is available to stream in full now on Prime Video – you can sign up now for a free 30-day Prime Video trial.

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