The first evidence of the existence of mythical animals dates back to the Upper Paleolithic era - it was at this time that people began to draw them on the walls of caves. Stories about them are preserved in epic tales. Ancient authors wrote about fantastic creatures; travelers and pilgrims met them during their wanderings. In the Middle Ages, heraldists willingly depicted them and writers described them in their "bestiaries". Then interest in mythical animals faded, and people had to meet them less and less - only sailors sometimes saw them emerging from the depths of the sea. But the 20th century unexpectedly stirred up a craze for fantastic creatures, for which biologists have come up with a special term "mythosomes". The book of two culturologists working under the common pseudonym Oleg Ivik tells about mythosomes - ancient and modern, about their relationship with people and about the history of their study.