Thaddeus' true fate may have been revealed in Fallout Season 2, Episode 7. Johnny Pemberton's character was introduced in Season 1 of the Prime Video show as an aspirant in the Brotherhood of Steel. Toward the end of the season, Thaddeus took a mysterious ailment from the Snake Oil Salesman (Jon Daly) to heal one of his wasteland injuries, which had some ongoing side effects.
In the final episodes of Season 1, after Maximus (Aaron Moten) and Lucy (Ella Purnell) cornered Thaddeus in their quest to retrieve Wilzig's head, Thaddeus stepped on a booby trap that left an arrow lodged through his neck. When he didn't instantly die, Maximus commented, "Thaddeus, I think you might be a ghoul."
Season 2 of Fallout continued this narrative for Thaddeus, following the slowly degrading character as he oversees a group of child ghouls, thinking he is one of them. Later, Thaddeus rejoins Maximus and goes on the run with him amid the Brotherhood of Steel's civil war, all the while his mysterious condition has persisted. Episode 7 of Fallout Season 2 established that Thaddeus may not be a ghoul as one suspected, but something much worse...
Warning - The rest of this article contains spoilers for Fallout Season 2, Episode 7.
Why Did Thaddeus' Arm Fall Off in Fallout Season 2, Episode 7?
Throughout Season 2 of Fallout, Thaddeus has presented with some ghoul-like symptoms, such as his radiation resistance and the degradation of his skin and face. However, he's also displayed other symptoms that are very un-ghoul-like.
After reuniting with the Ghoul (Walton Goggins) in Episode 7, Thaddeus peppered the older ghoul with questions about his condition, claiming they were "just a couple of ghouls... talking ghoul stuff."
At one point, Thaddeus questions why his nose hasn't dropped off, like other ghouls. He also shows the Ghoul the odd flesh mouth that had appeared on his chest, asking, "This is normal, right?" The Ghoul's horrified response makes it clear that it is definitely not a normal part of the ghoulification process.
Adding to Thaddeus's strange condition later in the episode is an instance where his entire arm drops off unexpectedly. Surprised by this turn of events, Thaddeus looks to the Ghoul, asking, "This sort of thing happens to folks like us all the time, right?", to which the Ghoul doesn't look confident.
Losing limbs unexpectedly is not typically a ghoul symptom - in fact, ghouls are known for their regenerative healing abilities. So this moment makes it more evident than ever that whatever mutation process Thaddeus is going through, it's not turning him into a ghoul.
What Is Thaddeus Becoming in Fallout Season 2?
So if Thaddeus is not a ghoul, what is he?
A common theory is that the remedy the Snake Oil Salesman sold Thaddeus in Season 1 wasn't Ghoul-related but was actually some form of the Forced Evolutionary Virus (FEV). The FEV has become quite a focus in Season 2 of Fallout, so having one of the main characters be explicitly impacted by it in real-time seems like a smart way for the show to demonstrate the effects of this virus.
If this is the case, it's more likely that Thaddeus is transitioning into a super mutant, or even something worse, like a centaur.
The subjects of the FEV have been introduced in Fallout Season 2, specifically in Episode 6, when the Ghoul is rescued by Ron Perlman's super mutant - the first instance of a known super mutant in the Prime Video series. Super mutants are a common occurrence in the Fallout games (and are sometimes even stronger than Deathclaws). They are created after a regular human is exposed to the Forced Evolutionary Virus.
Another breed of mutant that Thaddeus could be transitioning into is a centaur. Centaurs are mutant hybrid creatures that evolve after humans and other animals, such as canines, are exposed to the FEV, eventually transitioning into chimeras with a mangled human-animal appearance.
Centaurs have various appearances and evolutions in the Fallout games, with some growing multiple limbs (and even heads), while others lose limbs.
Is Thaddeus a Centaur? Or Is He Really a Ghoul?
Given recent developments around Thaddeus in Fallout Season 2, it's becoming increasingly clear that he is not turning into a ghoul but is more likely becoming some kind of mutant.
Notably, the super mutants shown in the series so far, through Perlman's character, are overgrown humans who largely retain their appearance, with a green or yellow radioactive hue to their skin.
Thaddeus has so far not shown any of these symptoms, which suggests he's transitioning into a centaur instead, given that his mutation is causing extra growths and the loss of his other limbs.
With the way things are going, whenever Thaddeus evolves into his final form, it likely won't be a pretty sight.
