Pareidolia
Pareidolia (/pærɪˈdoʊliə/ parr-i-DOH-lee-ə) is the bias of the human mind towards perceiving familiar patterns in stimuli even when the patterns are not really there.
Common examples are perceived images of animals, faces, or objects in cloud formations, the "man in the moon", the "moon rabbit", and hidden messages within recorded music played in reverse or at higher- or lower-than-normal speeds.
Etymology
The word comes from Ancient Greek.