Ripley does on occasion - tiny little growls and whines.
Dakota snarls in his sleep. It's disturbing since he's been sleeping with his head on my pillow. The first night he did it, I turned on the light and he didn't wake up. All I saw were bared teeth and his eyes open, but rolling back into his head. I was afraid to touch him at first, I thought he was having a seizure. I finally touched him and he woke up, the lips covered the teeth again and he just gave me this weird, sleepy look.
I've gotten used to it, but my friends find it freaky.