Since his introduction into the Marvel Cinematic Universe, Thor, God of Thunder, has changed dramatically. Particularly his hair and eyebrows. Did you think we were talking about his transformation from spoiled prince to humble king? While Thor did change quite a bit as a character during his arc in the MCU, more importantly, his appearance changed as well. He mostly donned armor and clothes that were modest, and at most showed off his muscular arms, but a few times, including one notable scene in Avengers: Age of Ultron, he showed off his muscular abs.
One Reddit user started a thread asking, “what is your canon explanation for the change in Thor’s eyebrows?” And the users of Reddit stepped up, with close to a thousand responses discussing not only Thor and his appearance, but the Asgardian fashion choices as well. So, what is the deal with Thor’s eyebrows?
Thor as a teenager
The first time we meet him in Thor, excluding the opening scene when he is a child, Thor is a young adult. And while he might be 1500 years old, as one Reddit user in the thread pointed out, “Loki and Thor are still just teenagers by Asgardian standards.” It is pretty hard to deny that in Thor he acts like a teenager, causing all sorts of ruckus with the Frost Giants. And he has very blond hair, with blond eyebrows and a blond beard to match. He also has a lot of teenage-esque angst.
Thor as a young adult
After the events of his first movie, Thor actually matures a bit and starts to function as a young adult. And as befitting his age, he stops dyeing all of his hair blond, and maintains a more natural, dirty blond hairstyle. He also stops dyeing his eyebrows and beard. And he also eventually gets a haircut at the (shaky) hands of Stan Lee while on Sakaar.
Asgard fashion also changes quite a bit after Thor, particularly after Hela arrives and stirs things up. Gone are the beautiful, flowing dresses and fancy armor, replaced with more simple garb better suited to hiding from Hela in the mountains.
Thor in middle age
By the time we see him in Avengers: Endgame, Thor has been through some stuff. His mom and dad died, and then he had to kill his sister and blowup Asgard, Loki died (for real this time), Thor fought Thanos (should have gone for the head), and then he fought Thanos again (went for the head this time) only for it to be too late to save everyone. So, it is not really surprising to discover Thor has embraced middle age, complete with beer gut and a hairstyle The Dude himself would be proud of.
And Thor’s eyebrows? Well, Reddit has several ideas about that. Several users believed Darcy and Jane flat out told him how ridiculous he looked, while some believed it was due to spending more time on Earth, away from Asgardian magic that kept his eyebrows blond. Many users simply said it was natural changes during puberty.
However, the most popular theory, and the one that makes the most sense in the MCU canon, was Loki playing a prank on Thor. One user stated, “If we ever get a reunion, I want Loki to list out hundreds of things he’s sorry for, and to drop ‘convincing you to bleach your eyebrows’ to be slipped in there for a canon explanation.” Since Loki is by far the most fashionable Asgardian, it makes sense Thor would go along with this suggestion. Hopefully, either Thor: Love and Thunder or the second season of Loki, will confirm this completely on-brand theory.