Cryptids are animals or other beings that cryptozoologists believe may exist somewhere in the wild, but whose present existence is disputed or unsubstantiated by science. Cryptozoology is a pseudoscience and has been widely critiqued by scientists. The subculture is regularly criticized for reliance on anecdotal information and because in the course of investigating animals that most scientists believe are unlikely to have existed, cryptozoologists do not follow the scientific method. Many scientists have criticized the plausibility of cryptids due to lack of physical evidence, likely misidentifications and misinterpretation of stories from folklore.

While biologists regularly identify new species following established scientific methodology, cryptozoologists focus on entities mentioned in the folklore record and rumor. Entities that may be considered cryptids by cryptozoologists include Bigfoot, Yeti, the chupacabra, the Jersey Devil, the Loch Ness Monster, and the Mokele-mbembe.