It's dark because he's a humanoid fox and she's a humanoid bunny. I'm an Earther. We still have some foxes in the wild where I live. Very few but some.

Foxes hunt rabbits and other rodents. Pretty viciously. They jump up in the air and sort of pounce, land on their prey, then bite them in the neck and shake them until they die. I've seen a fox kill a rabbit before. Not pretty. Rabbits actually do this creepy death shriek when they get attacked.

I think that's what op means. They may walk and talk but they evolved from animals that were natural enemies. Predator and prey. Aggressor and victim.