To dream of a deer represents an aspect of your personality that is unaware or naive. A deer may also reflect how you are unprepared for a problem. You might be "too nice" about something or aren't being savvy enough.
A deer is a sign that you need to become better informed or that you don't realize a potential danger. A deer also reflects innocence, gullibility, or vulnerability to aggression from others. You are too open to being victimized.
Example: A man dreamed of seeing a deer eating grass. In waking life he had been warned about a coming disaster and ignored it.