Do unicorns exist??

[badkuk]

If you mean by nature, and not via genetic manipulation/mutation via radiation, etc., no they don't. The closest thing i can think of that has the characteristic single long horn on the forehead are narwhals

http://en.wikipedia.org/wiki/Narwhal

As as wikipedia page states, some narwhals even have two horns. Which make them extra horny. :D