DJ growls often. Soemtimes for no reason that I can see he’ll turn on Curly Sue, growl at her, then chase her. She runs away a few feet then stops, and he goes about his business. He growls at me too, if I reach into their pen and he sees my hand but does not realize that it is me. Then he smells that it is me and will lick my hand as if to say "Oops Dad, sorry, did not know it was you". If I ever have the scent of another rabbit on my hands he’ll growl too.
The growliest bunny I’ve ever met is a little 3 pound lionhead named Godiva (what is it about lionheads anyway?). She’s been to our house twice for overnights before and after surgeries, so when we get her back from the vet she is MAD. After her spay, when I tried to get her into the carrier to take her back to her foster home, it was growl growl grunt honk growl. I finally put on my gardening gloves and just grabbed her to get her in the carrier. I think she dislikes us :-}