The Cheshire Cat from Alice in Wonderland. I did all of my fingers except for my middle with a water/dry marble technique. I followed this tutorial on More Nail Polish. Except instead of using a thick piece of plastic, I placed wax paper in the water. When my marble was ready, I cut a hole in the paper and pulled it out. The water drained and the marble landed on the wax paper. The marble itself came out very well, but the transferring to my fingers was a little difficult. Practice makes perfect though.
For the marble, I used L.A. Colors Nuclear Energy and Sally Hansen Lacey Lilac. I painted on a base coat of Nuclear Energy then added the marble. The Cheshire Cat smile is a base coat of Sinful Colors Black on Black then Snow Me White and Ulta Sun-sational.
L.A. Colors retail for around $1 and can be found at most Dollar stores. Sally Hansen Xtreme Wear retails for $2-3 at Walgreens, Walmart, Riteaid, Target, and Ulta. Ulta Nail Lacquer retails for $6 at Ulta. Sinful Colors retail for $2 at Walgreens (online/in store) and Target (in store). They're also available for $2.50 at Cherry Culture.