In the Fallout TV show on Prime Video, there is no fully revealed, speaking super mutant character yet in season 1.

What the show has shown so far

  • Season 1 mostly teases super mutants instead of introducing a clear, named one on screen.
  • There is a briefly glimpsed, heavily mutated corpse in an Enclave-related scene that many fans interpret as a super mutant body, but it is not identified or characterized in the show.

Who might become the first major super mutant

  • A major fan theory is that Thaddeus, the Brotherhood squire who injects himself with a mysterious serum in episode 7, is being set up to transform into a super mutant rather than a ghoul.
  • The serum is strongly implied to be some form of FEV (Forced Evolutionary Virus), the same experimental agent that creates super mutants in the games and in the TV series’ lore.

Super mutants in the show’s lore

  • In the TV continuity, super mutants are humans transformed by exposure to variants of FEV, which grant extreme strength, toughness, and resistance to radiation and disease.
  • A Vault-Tec corporate meeting features West Tek executive Leon Von Felden talking about using a vault to create “super mutant” soldiers, foreshadowing that proper, on-screen super mutants are likely coming in later seasons.

So, who “was” the super mutant?

  • If the question is about a clearly shown, recurring super mutant character in season 1, there is none yet.
  • If the question is about who is being set up to become the show’s big super mutant, current evidence and fan discussion point to Thaddeus as the most likely candidate for season 2.

In short: season 1 only teases super mutants; Thaddeus is the prime suspect to become the first major one on screen.

Information gathered from public forums or data available on the internet and portrayed here.