Armoured and charging, the rhinoceros is read as unstoppable force and a thick skin. It can stand for pressing ahead without looking, or for a wish to be less easily hurt.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.