Robert Callaghan
Yokai Full Body
Alias(es) Yokai
Appeared in Big Hero 6
Status Incarcerated
Actor James Cromwell

Professor Robert Callaghan was Tadashi’s mentor. He stole Hiro Hamada's Microbots and became the villainous Yokai to take revenge on Alistair Krei.


Big Hero 6

When Hiro visits the university for the first time, he is star-struck by the world-renowned roboticist—while Callaghan immediately sees the potential in the 14-year-old prodigy, encouraging him to put his brain to better use. He later convinced Hiro not to sell Krei any of his Microbots, in which Hiro declines Krei, he later starts a fire and steals the Microbots in which Hiro's Brother tries to save him, but it kills Tadashi, and Callaghan fakes his death (which means he used the Microbots to escape).

During the recreation of Hiro's microbots, and then tries to kill Hiro and Baymax for witnessing his creation, he later tries to Kill Wasabi, Fred, Honey Lemon, and Go Go for witnessing his Microbots to bring in a mysterious part of a certain machine as if he plans to use it for something classified. On a Quarantine Island The Gang unearth's a project called "Silent Swallow" which is what Callaghan was once a part of with his daughter Abigail, when he was exposed, he expressed that Tadashi was a fool to try to save him.

After he escaped a rampaged Baymax he attacked Krei with his machine, and Microbots to get revenge for his daughter's disappearance. But the Big Hero 6 interferes and then he was arrested by the law, and as he sees his daughter being carried into the ambulance Alive, he then realizes he has dishonored his daughter and himself by the crimes he had committed.

Character traits

He comes off at the beginning as a supportive, kind, and a calm man, but at the parts of the movie as Yokai he shows he is sadistic, Cruel, cold hearted, cowardly, and vengeful monster that will stop at nothing to get his personal vendetta. Even if it means killing an innocent by stander.


Appearances/Voice Actors

Behind the scenes

To be added


  • In the comics he is known as Lord Deathstrike.
  • James Cromwell is known for being George Stacey on Spider-Man 3, but his most famous role is Arthur Hogget on Babe (1 and 2).


Big Hero 6

Promotion and Concept Art