Since Baymax of was programmed to be a healthcare robot, he naturally has an aversion to injuring people, much less killing them. Hiro gets around this by removing Baymax's original Personality Chip so he could be ordered to kill Yokai. When Baymax later comes to his senses and realizes what Hiro did, he physically locks Hiro out from accessing his Personality Chips to prevent Hiro from forcing him to kill again.
The rest of the titular team doesn't agree with Hiro's actions either, and after he grows out of his Revenge Before Reason mindset, this trope becomes more or less their code.
Manolo from The Book of Life, is firmly opposed to the idea of killing the bulls he fights, even though it earns him the ridicule of his family and the townsfolk, sans Maria.
The Hunchback of Notre Dame: Quasimodo refuses to kill anyone. There is a moment in the first film where he held the dagger he disarmed from Frollo and threw it and gave him a speech about Frollo being the monster instead of stabbing him. He even saved him when both Esmeralda and Frollo were about to fall.
Averted in The Incredibles. None of the Incredibles have any problem using deadly force in self-defense, and a lot of mooks die as a result. Bob does stop short of deliberate murder even in the grip of his Unstoppable Rage at believing his family was just killed, however. Helen even outright spells it out to the kids that the mooks are not holding back, won't care that they're just kids and they can and should defend themselves and each other, if need be.
Megamind knew that Metro Man went by this rule, always sending him to jail. It was one of the things that made their battles seem like a game to him. Unfortunately, when he created Titan to take Metro Man's place, he didn't anticipate Titan making his own rules.
