You can replicate any picture in royal icing. Use either a picture you have or find a picture on the internet. Modify the size on your computer to fit the cake you're making.
There are a few different ways to do this, but this works for me.
Tape the picture on the back of a cookie sheet or some kind of board. Tape a piece of saran wrap on top of the picture.
Using black royal icing, outline the picture with a small round tip like #2. Allow this dry for about thirty minutes.
You will need to tint your royal icing to match the colors of your design. The picture is filled in with thinned out royal icing. This is referred to runout icing. You simply add cold water to the royal icing until it is the consistency of thin hand cream. Not watery.
Fill in each section of the design with the appropriate color by going back and forth from one side to the other until the area is filled. Use a toothpick to pop any air bubbles.
When your design is complete, it could take 24 hours or more to dry depending on the humidity. You can make this up to 2 weeks in advance. When you are ready to add the design to the cake, place it on top of the counter or other surface and carefully slide the design off while peeling off the saran wrap. You can turn the design and do this on all sides until the design comes free. Treat it gingerly so not to break it. Once your cake is iced, you can simply place the design wherever you like.
Each color is placed in a separate cake decorating bag.