For my daughter’s 5th birthday she wanted a Little Pet shop frog cake. Firstly I started with a Large rectangular sheet cake pan (16 x 19 I think) but any size works. I used 3 boxes of cake mix and covered the entire cake with vanilla icing.
Then I found a picture that she liked in a coloring book and drew it on the base icing with a toothpick. I decided what colors were needed and mixed the white with food color. Using a butter knife and sandwich bags (cut the tip of the corner to squeeze icing out), I colored in the picture that I drew. Then I sprinkled the frog with green sugar sprinkles. Voila!