Therian or otherkin, yes
Phantoms are not something every therian experiences etc. and just that feeling, maybe that discontent with physical species is what matters.
Wiki is not the best source for information about all this, as most related articles mix serious scientific statements with something that sometimes is in direct conflict with them (please be careful, there's a lot of new age magic thingies around, you don't want to waste time and effort on that--they're inconsistent). However, you might want to read that:
http://en.wikipedia.org/wiki/Fantasy_prone_personality#Characteristic_features- check if you have 6 or more symptoms. Be
critical about them! Remember that "may" doesn't mean "does", it's just something that is an option, also remember that the symptoms are
necessary, but they aren't
sufficient to say you have FPP. If you do, you may be otherkin. Of course if something doesn't seem clear you can always ask
There's also
Creative Experiences Questionnaire (CEQ, 25 questions) and even more complicated Inventory of Childhood Memories and Imagining (ICMI, 52 questions). The latter can be found in: S. Wilson and T. Barber, Vivid Fantasy and Hallucinatory Abilities in the Life Histories of Excellent Hypnotic Subjects (“Somnambules”): Preliminary Report with Female Subjects, in
Imagery: Vol. 2: Concepts, Results and Application, E. Klinger (ed.), Plenum Press, New York, pp. 133-149, 1981, so getting Wilson's and Barber's "Imagery" (vol. 1 and 2) would be a nice idea if you're
really interested in the topic. Well, I don't think you are, but I'm posting it here anyway for future reference