How can I make the zebra look on a cake ?
I have done this two ways, I have used an air brush and sprayed on Zebra stripes. also you can use black jell color, wait till your iceing has set up and genly paint on the stripes, you have to be real gentle so not to puncture the iceing. If you do not have an airbrush, you can by the color in a can, works the same as airbrushing.
There are many ways it can be done. Julibel covered some of the many ways.
Check the first link on my signature, find "zebra stripes" and you will see a tutorial of what you are looking for.