Clean the cement deer with a simple garden hose to remove any existing dirt from the surface before you begin to paint. Allow the ornament to dry completely before you continue.
Apply a masonry primer with a paint brush to prep the surface of the deer ornament. Using a primer will help the paint adhere correctly and prevent it from being absorbed by the porous cement, which could cause a mottled effect in the finished appearance.
Paint the entire deer by applying an exterior latex paint in your chosen base color with a paint brush. You can tint these paints in any color you desire, but brown is a good color choice for a realistic looking deer ornament. Allow the base coat to dry completely.
Use a small paint brush and black and white exterior latex paints to paint details such as eyes, nose and any white markings onto the deer. Use a picture of a real deer as a guide.
Apply a clear acrylic sealer to the cement deer ornament when the paint has dried completely. Look for a clear sealer specifically made for outdoor use to extend the life of your paint job.