“Hello, I am Baymax, your personal healthcare companion. I was alerted to the need for medical attention when you said "ow!"”
―Baymax whenever he is activated
Baymax is the deuteragonist of the 2014 film, Big Hero 6 and Big Hero 6: The Series. and the main protagonist of the Disney+ 2022 series Baymax! He was an Android created by Tadashi Hamada to be a personal healthcare companion. After his creator's death, he joins Tadashi's younger brother Hiro Hamada to bring the man responsible to justice.
Background
Baymax was conceptualized by Tadashi as a prototype healthcare-providing robot nurse to be mass-produced, with a goal to improve healthcare around the world. He was constructed using equipment and funding courtesy of the San Fransokyo Institute of Technology. Baymax's artificial intelligence (which was based on a thesis by SFIT alumni, Wendy Wower) comes from a special chip with Tadashi's inscriptions. The chip is equipped with a caregiving matrix, and without it, Baymax can be conceived as an entirely different being. As programming would have, Baymax is instantly summoned by the sound of distress, and can only deactivate once his current patient states, "I am satisfied with my care."
Official Description
“Baymax cares. That's what he was designed to do. The adorable, plus-sized inflatable robot's job title is technically Healthcare Companion: With a simple scan, Baymax can detect vital stats, and, given a patient's level of pain, can treat nearly any ailment. Conceived and built by Tadashi Hamada, Baymax just might revolutionize the healthcare industry. However, to the inventor's kid brother Hiro, the nurturing, guileless bot turns out to be more than what he was built for—he's a hero, and quite possibly Hiro's closest friend. And after some deft reprogramming that includes a rocket fist, super strength and rocket thrusters that allow him to fly, Baymax becomes one of the Big Hero 6.[3]”