In this article, we discuss the phenomenon of crescent-shaped pendants dating back to the Late Roman Iron Age and Early Migration Period (3rd – 6th centuries AD). Placed on horse’s foreheads, these crescent-shaped pendants evidently embodied a mythological link between the moon and the horse. The same link is clearly reflected in linguistic data and folklore right up until the 20th century. We draw special attention to a horse with a white mark on its forehead called laukas (adj.), laukis (noun) in Lithuanian, which derives from the I-E root *louk- ‘shining, bright’, as also does the Latin luna (< *louksnā). Considering the data as a whole, we propose an unexpected link between the Baltic and Roman traditions.