What to name my new puppy?

I have two dogs and two cats. All my pets names start with R. Ringo and Rita are my two dogs, and rigby and rizzo are my cats. I am getting a new puppy in 5 weeks and I'm torn between an few names. i could stay with the beatles theme and go with Revolver and call her Revo. I could also go with Prudence, but no R. I'm ocd and that would bother me. another option, because rizzo is from grease the musical is to name the new puppy for a musical. the rocky horror picture show has a character named riff raff, or i could just name her rocky. Also from the beatles is rocky racoon, which i kind of like as a dog name. Help me choose please and thank you.