Black Donald is the Scottish devil.  He assumes many disguises and is often seen as an old man in a black suit.  He is proficient at all
jobs, except tailoring.  It is because when he is among the tailors, they close up shop and he never learns how to baste.  

Baste - to sew loosely with large running stitches so as to hold together temporarily. Black Donald's disguises never work because he cannot hide his cloven hooves.