1) Ape, Carnivorous

I have never encountered a man-eating ape during any of my game sessions, nor have I knowingly met any D&D player who has. I assume they’re here because I think Conan the Barbarian fought some once? But even if that’s true, I don’t think anyone can explain to me why encountering normal apes is a Very Rare occurrence, but a Carnivorous Ape is Rare…?