I call myself a unicorn because it has been my fDP's term of endearment for me since long before we discovered the poly community.
I have to admit, learning the more negative terms associated with it (naive, pet, being 'hunted' etc) makes me really dislike it. I still let her call me that, because she has for such a long time (2 years +) and it has a totally diff meaning
But I'd probably stop referring to myself as such! (which means changing the title of my blog