What is "taraxippus"

In Greek mythology, the Taraxippus (plural: taraxippoi, "horse disturber", Latin equorum conturbator) was a presence, variously identified as a ghost or dangerous site, blamed for frightening horses at hippodromes throughout Greece. Some taraxippoi were associated with hero cult or with Poseidon in his aspect as a god of horses (Poseidon Hippios) who brought about the death of Hippolytus. Pausanias, the ancient source offering the greatest number of explanations, regards it as an epithet rather than a single entity.