Thaddeus is an interesting character in the Fallout TV adaptation. A squire belonging to the Brotherhood of Steel, who bullied Maximus in the past. Only to get stuck accompanying him on the mission to recover Dr. Siggi Wilzig’s head.
He can be clever at times, particularly when he was fighting Maximus without needing any power armor. He can also be really stupid, like when he was threatened to kill a shady doctor that had just offered him a cure for his mangled foot. That “cure” gave Thaddeus a healing factor and enhanced durability.
Maximus suspects that Thaddeus has turned into a Ghoul, but is that really the case?
What happened to Thaddeus?
During his confrontation with Maximus, Thaddeus’ foot is crushed by Maximus’ power armor. Mangled with bones protruding out, Thaddeus limps across the Wasteland until he encounters a “snake oil” salesman in the episode “The Radio”. The salesman promises to give Thaddeus a special serum to fix his foot.
After he inhales the mystery serum, Thaddeus’ foot immediately begins to heal itself with no ill side effects. It isn’t until he finds himself at the KPSS radio station that he learns the serum did more than heal his foot.
After he accidentally walks into a trap, he survives getting an arrow straight through his neck. He’s even still able to breathe and speak. When he removes the arrow, his body starts regenerating. So what’s going on here?
What is Thaddeus now?
Maximus suspects that Thaddeus has turned into a Ghoul. However, many fans believe that the squire is actually mutating due to the effects of the Forced Evolutionary Virus (FEV).
FEV mutations start after direct exposure to liquid or injected FEV in labs, military facilities, or VATS. FEV usually leads to changes in height, muscle mass, even your entire bone structure at a rapid pace. The transformations can be brutal and last for days.
Meanwhile, ghoulification is a slower, gradual process. It’s the result of massive or prolonged radiation exposure. The victim needs to be kept alive while their body changes. Ghouls retain original height or body size, though they do lose their hair. Their skin rots away as their body takes on a corpse‑like appearance.
The key difference between an FEV mutant and a Ghoul
What sets mutants apart from Ghouls is how FEV affects their personality. Depending on what strain they took, FEV mutants could have reduced reasoning or increased aggression. They can retain their intelligence under certain circumstances.
A Ghoul on the other hand, keeps their original personality and memories. They are in danger of going feral, which is when a Ghoul loses their humanity while adopting animal-like behavior.
The show has never officially confirmed if Thaddeus is a Ghoul, a mutant, or something else entirely. So far, it’s looking like Thaddeus is turning into some kind of mutant, with that serum being a form of FEV. Thaddeus’ current status is unknown. He abandons the Brotherhood of Steel out of fear the faction would kill him. Now if he reappears in season 2, it’ll be interesting to see if he displays any other abilities or physical mutations. For now, Thaddeus’ transformation is more in line with a FEV-style mutation than being ghoulified.
