I love unicorns if you haven't figured that out yet.  I have a few different unicorn shirts.  One of my favorite shirts is one I purchased about a year ago.  It's from ASOS (they always have a bunch of unicorn items).  When I found this cookie cutter and it matched my favorite shirt, I knew I had to have it.

I outlined the cookie with black icing and then flooded it with white icing.  Once the icing was dry, I used watered-down food coloring to paint the horn to match the unicorn on my shirt.  Then I used black icing to add the lines on the horn, the eye lid, and nostril.  I used a food coloring marker to draw on the eye.