It is not large, measuring roughly 1.3 metres long and 0.76 metres wide, and it is easy to overlook. But the inscription carved into its face carries a quiet weight: two friars, Gyldas Bruoder and Laghlen Quely, had this tomb made for themselves in October 1676, and asked that anyone who passed by offer a single Ave Maria for their souls.

The plaque, described by Bradley and Dunne in their 1992 study as a mural plaque, is decorated with a carved chalice and host, symbols of the Eucharist that would have been immediately meaningful to any Catholic worshipper. Above the vernacular appeal for prayer, the stone opens with a line of Latin: "IHS Christe Fili Dei Vivi, Miserere Nobis", meaning "Jesus Christ, Son of the Living God, have mercy on us". The combination of Latin invocation and plain English request gives the monument an oddly direct, almost personal character. The year 1676 places it in a difficult period for Catholic religious life in Ireland, when the Penal Laws were beginning to tighten, making the friars' act of formally commissioning a tomb monument for themselves within their own friary a quietly significant one. A similarly decorated slab survives nearby in the east wall of the north transept, suggesting that this kind of commemorative stonework was something the community at Claregalway invested in deliberately, leaving paired markers of their presence within the fabric of the building.