Unicorn

According to Jim, unicorns do not exist in the world of Skin Deep.

In the Word of God the following questions and answeres are given:
 * I saw in one of the Orientations-Avalon pages that there was a spirally horn labeled "alicorn." You've mentioned before that there are no unicorns, but alicorn is the name for unicorn horn. What's up with that?
 * I never said that there didn't used to be unicorns.

So, it would seem that while no one thinks there are unicorns, they may have existed in the past. In fact they may be as extinct as Sphinxes and Dragons.
 * Are Unicorns really extinct or as extinct as Sphinxes?
 * The general consensus among the mythical community is that there are no unicorns. : D