1 box of yellow cake mix
2 cans of chocolate ready made icing
1 tube of another color icing (your choice)

Prepare cake mix as directed on box

Once the cake is done and cool use one layer for the cat's body. Cut out the head, ears and tail from the other layer of cake. Iced the cake and add head, ears, and tail with icing to keep them on the cat's body. Use another color icing to make the cat's ears, nose, whiskers, and mouth.
You can make a dog cake by making a shorter tail and maybe longer droopy ears.