Sound of fantasy horn (real) - Carnyx horn, Iron Age.

 https://m.youtube.com/watch?v=68Hds0OYrbg&ra=m

Time 8:27

https://www.thevintagenews.com/2017/06/06/the-carnyx-a-long-curved-instrument-used-by-the-celts-during-the-iron-age/ says -- Prior to 2004, fragments of only five such instruments had been preserved, from Germany, Switzerland, France, Scotland, and Romania, but in November 2004 archaeologists discovered more than 500 fragments of unique military and religious objects in a Gallo-Roman site at Tintignac, in southern France. These objects, all made of iron and bronze, included 10 helmets, a dozen swords and scabbards, iron spearheads, a shield, two animal heads, one foreleg, a cauldron, and seven carnyces. Once one of the carnyces was restored, it proved to be the most complete carnyx ever found.

wikiped -- Six of the carnyces had boar's heads, while the seventh appears to be a serpent-like monster. 

-- The carnyx (pl.: carnyces; /kɑːnɪks/, KAR-nicks) is a wind instrument that was common in Celtic cultures during the Iron Age, between c. 200 BC and c. 200 AD. It is a type of trumpet made of bronze with an elongated S shape, held so that the long straight central portion was vertical and the short mouthpiece end section and the much wider bell were horizontal in opposed directions. The bell was styled in the shape of the head of an open-mouthed boar or other animal.

The Celts used the carnyx in warfare, probably to incite troops to battle and to intimidate opponents, as Polybius recounts.[1] The instrument's significant height—typically around 1.8 metres (6 feet), standing as tall as its player—allowed it to be heard over the heads of the participants in battles or ceremonies.[2] The carnyx was not only used by the Celts but also by the Dacians in modern Romania, and depictions have even been found on a Buddhist sculpture in India, attesting to the far-flung connections of the Iron Age world.[3]

https://www.reddit.com/r/ArtefactPorn/comments/10dvmb3/a_nearly_complete_1st_century_bce_carnyx_found_in/ says -- A nearly complete 1st century BCE carnyx found in 2004 at Tintignac, France (the one in the left picture, with a reconstruction in the right). Fashioned as a snarling boar, the carnyx was a war horn used by the Iron Age Celts between c. 200 BCE and c. 200 CE