I had my cats first also. Mr. Bun-Bun had never been around other animals and quickly took it upon himself to declare that he was the boss. I never leave them unsupervised, maybe I’ll walk out of the room for a couple minutes but I don’t leave the house. Sometimes he chases them “playfully” – jumping and tossing his head. Other times he crouches down to the ground and runs at them so quickly they can’t escape which really freaks my poor cats out. Of course when he reaches them he just bumps into them but it still scares them.
A kitten might become great friends with the rabbit, but they can also be very playful and naughty, and usually go through a phrase where they are even more highly destructive than rabbits! I might try to get a full-grown cat from a shelter that is familiar with rabbits, if possible. Cats are lazier and there’s a chance they’ll just ignore each other, as people are saying here. I’ve been thinking about this too because one of my cats is dying, the other is pretty old 