Like in Stalker where the mutant dogs will turn tail and flee if they take too much damage or if you kill enough of their pack members. Red Dead Redemption's animals also ran away if a fight wasn't going their way.
Actually, Rockstar games are pretty good with this sort of stuff in general. I'm pretty sure you could shoot guns of of people's hands in RDR to make them put their hands up, or cause a fatal gunshot wound that would make them crawl around on their belly and call for help. Both GTA 4 and 5's enemies have injury states where they will take potshots at you with a pistol while bleeding on the ground or just passively clutch their wounds until they die.
I guess it wouldn't work in arcadey or linear games where the point is to kill everything on screen, but for anything more open-ended that tries to go for something approaching realism it'd be nice if the enemies you faced felt more alive and/or showed some basic survival instincts.
Yeah, up to at least AD&D 2nd Ed you were supposed to track everyone's morale to figure out when enemies would surrender or flee.
Well, monsters checked morale as a group, not every single one. First when they took their first casualty and again when they lost more than half their number. If they passed both, they would fight to the death. Monster morale was usually 6-8 and passed on a roll of 2d6. Undead had morale 12.
But nobody ever bothered to check morale, unless the DM remembered it to save the party when a TPK was about to happen. Too much fun slaughtering monsters when the fight was already won.