An effigial tomb is one bearing a sculpted likeness of the deceased, typically rendered in stone and placed within or beside the tomb chest, and this particular figure has puzzled historians long enough to generate competing attributions without settling on either.

Two candidates have been put forward. The first is Bishop John St. John, who held the see of Ferns between 1224 and 1253, a period when the Anglo-Norman reorganisation of the Irish church was well underway and episcopal patronage of stone carving was becoming more common. The second candidate is Adam de Northampton, who died in 1346, more than a century later, which would place the effigy in a rather different stylistic and political context. The gap between those two dates is not a minor discrepancy; it spans the entire early and high medieval periods in Ireland, and the figure's correct attribution would say something meaningful about when the diocese of Ferns was investing in this kind of commemorative stonework. Scholarly opinion, drawing on art historical and documentary sources, has not yet closed the question.