Like Absolutely Cuckoo, Wi' Nae Wee Bairn Ye'll Me Beget has two parts, both of which are sung by Stephin Merritt on the album. In live performance Stephin and Claudia sing the refrain together ('Wi' nae wee bairn ye'll me beget / Untwinkle, little ee / My ainly pang'll be regret / A maiden I will dee') but alternate in singing the lines in each verse, which brings out the dynamic of the song in sharper relief.
For anyone unfamiliar with Scottish dialect, 'Wi' Nae Wee Bairn Ye'll Me Beget' translates as 'With no small child you will me beget (i.e. sire)'. The 'shape-shifting' theme of the lyric ('Well I'll turn into a...') is common to many folk traditions. A widely known instance (since Disney did a [film] of it) is the shapechanging battle between Madam Mym and Merlin in T H White's The Sword in the Stone.
The 'little ee' and 'a maiden I will dee' (i.e. die) lines may be true to the phonetic spirit of many Scots ballads, but stretch the 'letter' of dialect pronounciation.