Its head is hollow; in the space underneath, which was filled with soil and plant matter when found, are three rivets that would have attached it to a larger object, probably a helmet.

[2][3] The head is elongated, capped by a prominent mane dividing the skull, and terminates in a blunt snout, defined by three grooved and gilded lines.

[1][2] The boar's two small eyes are formed with lentoid cabochon garnets, set in beaded gold filigree work with a double collar.

[9] Boar iconography is also found on helmets from the period, typically on the crests, as with the Benty Grange, Wolaston and Guilden Morden examples,[10][11] or at the ends of the eyebrows, as on those from Sutton Hoo and perhaps York.

[2][5][12][note 1] The Horncastle fragment, with its lentoid eyes, tusks, and defined mane, is stylistically similar to the boar atop the Benty Grange helmet.

[2][5] Taken in context, the boar would probably have adorned an early model of the "crested helmets" known in Northern Europe in the sixth through eleventh centuries AD.

[5] The boar was an important symbol in prehistoric Europe, where, according to the archaeologist Jennifer Foster, it was "venerated, eulogised, hunted and eaten ... for millennia, until its virtual extinction in recent historical time.

[21][22] Boar-crested helmets are depicted on the turn-of-the-millennium Gundestrup cauldron, discovered in Denmark, and on a Torslunda plate from Sweden, made some five hundred years later.

[20] The boar persisted in continental Germanic tradition during the nearly 400 years of Roman rule in Britain, such as in association with the Scandinavian gods Freyja[24][25] and Freyr.