The Dorset Ooser (/ˈoʊsər/) is a wooden head that featured in the 19th-century folk culture of Melbury Osmond, a village in the southwestern English county of Dorset. The head was hollow, thus perhaps serving as a mask, and included a humanoid face with horns, a beard, and a hinged jaw which allowed the mouth to open and close. Although sometimes used to scare people during practical jokes, its main recorded purpose was as part of a local variant of the charivari custom known as "skimity riding" or "rough music", in which it was used to humiliate those who were deemed to have behaved in an immoral manner.
The Dorset Ooser was first brought to public attention in 1891, at which time it was under the ownership of the Cave family of Melbury Osmond's Holt Farm. After travelling with Edward Cave to Somerset, the Ooser went missing around 1897. Since then, various folklorists and historians have debated the origins of the head, which has possible connections to the horned costumes sometimes worn by participants in English Mummers plays. The folklorists Frederick Thomas Elworthy and H. S. L. Dewar believed that the head was a representation of the Devil and thus was designed to intimidate people into behaving according to the local community's moral system. Conversely, the folklorist Margaret Murray suggested that it represented a pre-Christian god of fertility whose worship survived in Dorset into the modern period, although more recent scholarship has been highly sceptical of this interpretation. The etymology of Ooser is also disputed, with various possibilities available.
In 1975 a replica of the original Ooser was produced by John Byfleet, which has since been on display at the Dorset Museum in Dorchester. This mask retains a place in Dorset folk culture, being removed from the museum for use in local Morris dancing processions held by the Wessex Morris Men on both St. George's Day and May Day. The design of the Ooser has also inspired the production of copies which have been used as representations of the Horned God in the modern Pagan religion of Wicca in both the United Kingdom and United States.