Cryptids are mainly plants, animals, and other eukaryotes not recognized by the scientific community or thought to be extinct but some believe they are still alive today. Cryptids are creatures whose existence is based on alleged sightings with varying degrees of supporting evidence. Some of these alleged creatures have origins spanning to that of antiquity, with their presence believed to have been recorded in myth and legend, while others are thought to have taken new evolutionary paths and evolved from previously existing creatures into new variations.

Cryptozoology is the study of cryptids. It is an attempt to analyze contemporary sightings of creatures in a scientific fashion. Cryptozoologists are those that study cryptids and cryptozoology. Cryptozoology is not recognized as a branch of science by mainstream scientists. That being said, cryptobotany, a branch of botany, is the study of plants whose existence is also not recognized by the scientific community.