Cryptozoology is the scientific study of hidden animals.
Classification (from monstrous.com)
Type 1 :
Animals known from native tradition (folktales, mythology, …). Most mystery animals dealing relevant to cryptozoology are known by tradition and collective memory, and therefore possess a vernacular name (or several ones) among the natives. Artistic representations of animals also fall into this category, unless they are directly related to an actual observation, thus relevant to the following category.
Type 2 :
Animals known by witness' account (sightings). By analyzing visual, auditive, olfactive, tactile, and even gustative information, we can come up with a more accurate description of the specie.
Type 3 :
Animals known by interaction with matter. Tracks and trails, photographies and movies, sonar echoes, injury marks, hybridization marks, evidence of symbiosis with another species or modification of the environment can be considered as potential associated “proofs”.
Type 4 :
Animals known by anatomical fragments: hears, feathers, fur, bone fragments, excrements, blood drops, tissue samples, …
Type 5 :
Animals known by an actual complet specimen. There are some controversial species relevant to cryptozoology, although they have been described from a specimen : for instance, the pygmy elephant (Loxodonta pumilio).
So you want to be a cryptozoologist?