HEAD TRANSPLANT

A head transplant or full body transplant is an experimental surgical operation involving the grafting of one organism's head onto the body of another. In many experiments, the recipient's head has not been removed, but in others it has been. Experimentation in animals began in the early 1900s. As of 2025, no lasting successes have been achieved.
https://www.youtube.com/watch?v=eW2RVq5ufgw
A Monkey Head Transplant (Part 2/2)
https://www.youtube.com/watch?v=VtDQc-4wGvM
Russian scientists successfully reanimate dead dog's head (1940)