Becoming an animal is traditionally read as instinct taking over from reason. Which animal you become is the clue: its nature is read as the quality you are growing into, or the one you fear in yourself.
Does the traditional reading fit your dream, or did it mean something else to you?
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.