One of the biggest shows of the year, Robert Kirkman's Invinciblehas become a smash hit adaptation on Amazon Prime. The adaptation of the original comic from Image Comics about teen superhero Mark Grayson and the complicated relationship he has with his father Omni-Man has exploded into success, with Season 2 already greenlit for production.

RELATED: Invincible: 10 Storylines That Could Appear In Season 2

While fans are waiting patiently for Season 2, rumors are buzzing about what might be expected. With the Amazon show featuring an impressively large cast of star-studded voice actors, the hype has been building around who could make their way into Season 2.

10 Seth Rogen Was Great As Allen The Alien

Allen the Alien Seth Rogen Invincible

The first season of Invincible was full of talented actors, and when the cast list for the show was originally announced, fans of the comic were excited to see how all these actors would fit into the show. One of the most surprising castings was Seth Rogen appearing as Allen the Alien, a Champion Evaluation Officer for the Coalition of Planets.

One of the last of his kind, Allen spends his time evaluating other planets, in case they were ever to come under siege by the Viltrum Empire. Once he learns about the events of the season finale, Allen tells Invincible that he will be very important to the Coalition of Planets and any attempt to stop the Viltrum Empire, which means fans probably will see the beloved one-eyed alien again in Season 2.

9 Phoebe Waller-Bridge Has Already Been To Space

L3 37 Phoebe Waller Bridge Star Wars Story

One of the most sought-after women in Hollywood, Phoebe Waller-Bridge, would make a great addition to the cast of Invincible. Her work on her hit show Fleabag aside, Waller-Bridge already has voice acting credits under her belt thanks to her role in Star Wars: A Solo Story.

Since finishing Fleabag, Phoebe Waller-Bridge signed a long-term deal with Amazon for 3 years of work, which could see her lend her talents to the Prime Video network. Either as a new hero potentially joining the Guardians of the Globe, or another character in the developing saga of Robot, Waller-Bridge would make a dynamite addition to the cast.

8 Jeffrey Dean Morgan Has A Connection To Robert Kirkman

Jeffrey Dean Morgan Walking Dead Robert Kirkman

Robert Kirkman claimed in an interview that the first casting they made for the show was Steven Yeun as Mark Grayson. Kirkman says that he was confident in bringing Yeun onto the project despite his small voice acting experience, because of their shared time on another one of Kirkman's incredibly famous shows, The Walking Dead.

RELATED: Invincible: 5 DC Villains He Could Beat (& 5 He'd Lose To)

With this in mind, perhaps Kirkman will pluck another TWD alumni for a role in Invincible Season 2. Jeffrey Dean Morgan is known for his commanding presence on-screen, which surely he could translate to the sound booth. With plenty of heavy-hitting superhumans set to appear to challenge Invincible in Season 2, Jeffrey Dean Morgan could really land himself a breakout role.

7 Will Arnett Is Already Familiar With Comedic Crime-Fighting

Will Arnett Lego Batman

An actor who is accustomed to the world of voice acting, Will Arnett would surely make a great addition to the cast. Well-known for his role in the sitcom Arrested Development, Arnett has achieved even more plaudits for the roles he has lent his voice for, including the titular character in the Netflix show Bojack Horseman, as well as The LEGO Batman Movie.

With more superheroes bound to step forward to fill the roles left by the Guardians of the Globe and Omni-Man, it isn’t hard to see Will Arnett lending his talents to the new season. A seasoned actor who understands the line between comedy and superhero heroics, he seems to be a perfect fit.

6 Bill Hader has A Range Of Voice-Acting Talent

Bill Hader Invincible

Another actor known for his comedic talents, Bill Hader has an underrated but expansive career in voice acting. Known for his time on Saturday Night Live and his HBO hit show Barry, Hader also has voice acting credits on Marvel’s MODOK show, Inside Out, and Cloudy With A Chance of Meatballs.

Where Hader can find room to work in Season 2 of Invincible is a different question. His flexibility as a performer and background in comedy and improv could make him a very valuable asset to the cast, providing comedic relief in very tense moments as the show is known to do.

5  Regina King Was part Of An Animated Cult Classic

Regina King Boondocks Invincible Season 2

Robert Kirkman, creator of the original Invincible comic and head writer of the show, has spoken about the importance of representation in comic books. With this in mind, fans could potentially expect to see more Black voice actors join the cast, due in part to Amber’s family. Amber is sure to feature in the next season, and there is potential for her family to be introduced into Season 2.

RELATED: Invincible: 5 DC Heroes He Would Defeat (& 5 He Would Lose To)

In terms of casting, Oscar-winner Regina King would be a major powerhouse addition to the cast. With a long resume of voice-acting credits, including a starring role in The Boondocks, Regina King would really bring a different level to the show.

4 Seth MacFarlane Is No Stranger To Voice Acting

Seth MacFarlane Family Guy American Dad

A titan in the animated TV business, Seth MacFarlane would be an incredible addition to the cast. His dynasty is still ongoing, with shows such as Family Guy and American Dad having been on the air for a combined 38 years and counting. MacFarlane also has a foothold in nerd culture, having written and starred in The Orville, a show seen as his own homage to the Star Trek universe.

In terms of his role in the Invincible universe, MacFarlane would fit in anywhere. The range of characters he’s used to playing on his shows means he’s no stranger to far-out aliens, or even tortured traumatized superheroes, both of which we’re bound to see in Season 2 of Invincible.

3 Awkwafina Would Be A Great Addition To The Cast

Raya and the Last Dragon Awkwafina Voice Acting

In an interview with The Daily Progress, Robert Kirkman admits how clueless he had been to the subject of representation in comics beforehand, and how he is very interested in telling stories fans of all backgrounds can see themselves in. He added that when writing the original Invincible comics, the ethnic background of Mark Grayson was kept relatively ambiguous, and it wasn’t until Steven Yeun was cast in the main role that they decided to lean into his Asian-American heritage.

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With Season 2 in mind, some fans have speculated about the appearance of Olivier Grayson, Mark’s half-brother, in the show. Should he be introduced in Season 2, it could be assumed that his voice actor would also be of Asian heritage, making Awkwafina a great potential casting. With her eccentric personality and a great performance off of the back of Raya and the Last Dragon, Awkwafina would make a great addition to the Grayson family.

2 Alan Tudyk is incredibly versatile

Alan Tudyk Droid Star Wars Rogue One

Another actor with a long list of accomplishments in voice acting, Alan Tudyk is incredibly versatile. From DC Universe's Harley Quinn, to the Star Wars franchise, Tudyk is known for his range. When Season 1 of Invincible was announced, many fans tipped Tudyk to play the role of Robot and were surprised to find him not included in the cast.

Season 2 may present an opportunity to change this. Season 2 of Invincible will surely introduce plenty of different supporting characters from the comic in a number of different ways. To have Alan Tudyk as part of the cast would give the writers the ability to bring any of these strange and plentiful characters to life very easily.

1 J.K Simmons delivered a standout performance last season

Omni Man Jk Simmons Invincible

While this may seem like an obvious addition to the list, it still needs to be said. Due to the events of the season finale, It is currently unknown just how much of J.K Simmons' Omni-Man fans can expect to see in Season 2 of Invincible. With Omni-Man seemingly off-planet, fans may have to wait for a short hiatus before they see the Viltrumite on-screen again.

In the original comics, Omni-Man leaves Earth and goes and establishes himself on another planet, waiting a significant amount of time before reaching out to Mark again. Hopefully, it doesn't take as long in Season 2, as J.K Simmons delivered a standout performance last season, with his depiction of Omni-Man bringing the twisted character to life fantastically.

NEXT: Invincible: 10 Things You Didn't Know About Omni-Man's Power Level