Robert Callaghan
Background information
Feature films Big Hero 6
Television programs
Video games
Park attractions
Voice James Cromwell
Performance model
Character information
Other names Callaghan, Yokai
Personality Cunning, elusive, mysterious, ruthless, vengeful, bitter, deranged
Appearance Tall, wrinkled skin, gray hair
Occupation Professor later supervillain
Affiliations Bad
Goal To avenge his daughter's death.
Home San Fransokyo
Friends His daughter (somewhat), Hiro and Taddashi (formerly)
Enemies Hiro Hamada, Baymax, Alistair Krei, Go Go Tomago, Wasabi, Honey Lemon, Fred
Minions Microbots
Likes His daughter, science, robotics, vengeance
Dislikes Alistair Krei, his daughter in danger, abuse of science
Powers and abilities Telepathic control over Microbots
Weapons Microbots
Fate Sees his daughter one last time before facing imprisonment.
Typical Saying "I want my daughter back!"

Professor Robert Callaghan, better known as Yokai, is the main antagonist of Big Hero 6. He is the head of the San Fransokyo Institute for Technology and is voiced by James Cromwell.

Role in the filmEdit

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  • He is based on Lord Deathstrike from the original Big Hero 6 comic books. This would make him the first Disney villain to ever have roots from Marvel Comics.
  • His alias, Yokai, means "spirit" or "demon" in Japanese.
  • Callaghan acts as a dark counterpart to Hiro. Both are brilliant inventors who end up suffering a tragic loss of a loved one (Tadashi for Hiro and Abigail for Robert). However, while Hiro eventually learns to accept his loss and change before he can fall into darkness, Robert stubbornly refuses to accept Abigail's loss, having been pushed too far into corruption to change. However, upon seeing his daughter while being arrested, he seems to show some regret, hinting that he may change or not.
  • In production, Callaghan was originally known as "Dr. Martin Lebur".
  • Among the scripts and concept arts of Yokai, some of them depicted Yokai with slightly different powers: Instead of using masses of microbots, he uses what appeared to be liquid living biomass that's similar to the Venom and Carnage Symbiotes from Marvel Comics, but how he controls them is nowhere to be different.
  • Originally, Professor Callaghan/Yokai was going to put together a team of San Fransokyo's greatest criminals including Mr. Yama, but was changed to a solo act.
  • His alias Yokai was never mentioned directly in the film, it is only in the merchandising of the film.