These are two ancient horns, made of gold and engraved (or embossed) with runes and pictures that seem to tell a story. Or maybe just look cool.
Also, they are horns that it seems like no one ever blew (one translation of one inscription is about drinking), and they are horns that are not there:
The original horns were stolen and melted down in 1802. Casts made of the horns in the late 18th century were also lost. Replicas of the horns must thus rely on 17th and 18th-century drawings exclusively and are accordingly fraught with uncertainty. Nevertheless, replicas of the original horns were produced and are exhibited at the National Museum of Denmark, Copenhagen, and the Moesgaard Museum, near Aarhus, Denmark. These replicas also have a history of having been stolen and retrieved twice, in 1993 and in 2007.
[via Archaeological Illustrations – apparently an edit of two scans from S.A.Andersen: Guldhornene, København 1945.]