When an animal speaks in a dream, it's a notable departure from ordinary dream logic — usually a signal that your own instinct or intuition is being given unusually clear, direct expression, using the animal as a mouthpiece.
An animal giving you advice or a warning
Worth taking seriously as a reflection of your own gut instinct on a situation — the animal's species and disposition often matching the specific quality of the message (a wise owl, a loyal dog, a cunning fox).
An animal asking you a question
Can reflect a question you're actually asking yourself, externalised — the dream using the animal as a way of examining your own uncertainty from a different angle.
A frightening or threatening speaking animal
Often points to an instinct or gut feeling you're actively resisting listening to — the fear in the dream reflecting discomfort with what your intuition is telling you.