Guys I think we’ve strayed miles away from what the term RPG actually means.
RPG stands for Role Playing Game, and derives from the tabletop RPGs like D&D, Shadowrun, Vampire etc.
In order to play a role, as the term stands, the player’s character needs to have social skills, or at least, be intelligent enough to talk. Otherwise there’s no “role” to be played.
The terminology of RPG when it comes to computer games has degraded over the decades with games like Diablo minimizing the role playing aspect while maintaining the RPG core combat mechanics (Gaining experience, leveling up). Today an RPG is mostly defined by its system than the actual role playing happening inside it, but still, rudimentary NPC interractions still exist (you still “talk” to NPCs to buy items, gain quests, etc).
In your case, I can totally see an RPG game borrowing the concept of Lion King, and it would make a very interesting game. However, you mentioned realism, and due to lack of explanation, I assumed you were referring to realism in all aspects and not just gameplay.
So my question is, when you are playing as an animal with no social skills, where is the RP part of the RPG? You can’t talk to anyone, nobody can give you quests, and there can be no inventory system. The storyline can only be delivered through a 3rd party narrative exposition, so your typical RPG quests are void. Wouldn’t it make more sense to create a platform game instead?
And this isn’t just about the scenario. In nature you see instant kills. If a lion catches up to a zebra, it doesn’t deal 100 damage to it, it snaps the zebra’s neck. If an elephant tramples a hyena, the hyena is done for, and no amount of hit points can save it. You can’t have a hit point system in a realistic environment. Again, the approach of a platform game for this amount of realism is preferable to that of an RPG game.
I doubt you can be as realistic as you want with the RPG approach. It needs to be surreal to be an RPG.