Isaac Hempstead-Wright is, of course, best known as Bran Stark in Game of Thrones, where he specializes in ominously telling the future and riding on peoples' backs. Since Thrones began, it's been fascinating to witness the development of the show's youngster cast members and while Hempstead-Wright may have been overshadowed by fellow Stark actors Sophie Turner and Maisie Williams, there's no doubt that he has developed hugely as an actor over the course of playing Bran Stark.
Game of Thrones is finally set to conclude with this year's season 8 and, like the rest of the cast, Hempstead-Wright will soon be seeking pastures new. In terms of both age and appearance, Hempstead-Wright already lends himself naturally to the role of young Loki and his experience on GOT also means that the actor is well-versed in the pressures that come with starring in an internationally popular franchise. Hempstead-Wright's time playing Bran Stark has also seen him excel with a character possessing a cold heart, devoid of emotion - a trait not all that unfamiliar to Thor's adopted brother.
Another member of Christopher Nolan's impressive Dunkirk cast, 31 year old Aneurin Barnard is considerably older than the other entries on this list, but a youthful face betrays Barnard's actual age. In terms of actors who actually resemble a younger Tom Hiddleston, it's difficult to imagine a more accurate pick than Barnard, who boasts the same chiseled cheekbones, haunting blue eyes and devilish dark hair that originally turned Loki into the MCU's most swoon-worthy villain.
Despite his obvious talent, Barnard has yet to land that big breakthrough mainstream role and would be an ideal option if Marvel are looking to avoid an actor who is already closely associated with another popular franchise. Indeed, the only obvious drawback to casting Barnard as a young Loki would be the fact that, in reality, the actor isn't too much younger than Hiddleston. This may not be a problem in the short term, but if Marvel Studios are hoping their Loki series will run for several seasons, Barnard's age could eventually present more of an issue.
Currently one of 2019's hottest acting properties thanks to his starring role as awkward high school student/sex therapist Otis in the Netflix smash Sex Education, Asa Butterfield has already enjoyed a tremendous career, despite his tender years. From his award winning turn in the title role of Martin Scorsese's Hugo to his more recent part in Simon Pegg and Nick Frost's horror/comedy Slaughterhouse Rulez, Butterfield has already amassed plenty of screen experience and has tackled a wide variety of roles.
Due to the success of Sex Education however, Asa Butterfield's profile may be rising faster than Marvel's TV division can keep up with, and it may not be long before the young actor has moved onto considerably bigger things. Nevertheless, there's no doubting Butterfield's acting credentials and he would almost certainly succeed as a more youthful Loki.
Not only is Alex Lawther another former Black Mirror star, the actor played a younger version of Alan Turing in 2014's The Imitation Game, tasked with portraying a junior Benedict Cumberbatch. Lawther also featured in Morgan Matthews' X+Y alongside Asa Butterfield but is perhaps most widely known as James in Netflix's The End of the F**king World, a young teen who runs away with a girl, harboring the morbid intention of killing her just for the experience.
In the wake of that role, Lawther began to draw attention as a serious up-and-coming acting talent, playing a lead character with a sinister streak, while simultaneously captivating an audience and inviting them to learn more about his character. At 23, Lawther is ideally positioned to take the next step in his acting career and a big opportunity within the MCU as young Loki would perhaps represent a natural progression from Lawther's success in The End Of The F**king World. As testament to the youngster's prodigious talent, the great Dame Maggie Smith herself is reportedly a big fan.