This damaged stone block, measuring just 34 by 26 centimetres, features an intricate relief carving of two opposing beasts with conjoined cat-like heads. Their tails curve into stylised vine leaves, whilst a delicate stem and another vine leaf spring from where their forelegs meet. The carving style dates to the 15th or 16th century, displaying the sophisticated decorative work typical of that period.

What makes this fragment particularly intriguing is its twin in Ramelton, where an almost identical piece can be found at the Church of Ireland parish church. Both stones originally came from Magherabeg Friary before being relocated to their current homes. The connection between these pieces hints at a shared artistic tradition or perhaps even the same craftsman's hand. An ink sketch preserved in the Ordnance Survey Memoirs at the Royal Irish Academy shows another carved fragment that once existed at St. Ernan's but has since gone missing, suggesting there may have been more pieces in this decorative series.

These architectural fragments serve as tangible links to Donegal's medieval past, when skilled stone carvers created elaborate decorative schemes for religious buildings. The survival of these pieces, though removed from their original context, offers valuable insights into the artistic sophistication of late medieval Ireland. The information about these stones comes from the Archaeological Survey of County Donegal, compiled by Brian Lacey and his colleagues in 1983, with updates added in 2008.