On to the letter Z and zooform phenomena.
Zooform phenomena is normally classified as a branch of cryptozoology, although not without controversy. The controversy comes from the fact that some cryptozoologists feel that zooform phenomena does not involve animals but rather mystical creatures, and so should be confined to its own body of study.
Essentially the phenomena is when an entity, whether physical or spiritual, adopts the form of an animal. This adoption of an animal's form could be either voluntary or purposeful or it could be the result of a curse or other involuntary process.
Perhaps the most well-recognized example of zooform phenomena is werewolves. A person transforms into a wolf or a man-wolf involuntarily when the moon is full. An example of voluntary transformation is when a Skinwalker dons the skin of an animal and transforms into that beast (or at least a somewhat deformed version of it).
Because animals that are a result of zooform phenomena are not really animals, these creatures are purportedly extremely elusive. Some people argue that zooform phenomena is why nobody has been able to produce convincing evidence of Bigfoot, Yeti, hellhounds, el Chupacabra, the Beast of Bray Road, the Owlman of Mawnan or the Mothman. These people reason that these creatures who take on animal-looking forms could indeed be quite intelligent, maybe even more intelligent than us, and so they can elude capture and detection most of the time.
It's an interesting theory to say the least. I think most people are uncomfortable with it since we as humans want to believe we are it, we are the supreme beings on this planet and there are no others that could outsmart us.
Can anyone think of other examples of zooform phenomena?