A very short-tempered Dwarf, but not for the usual straightforward reason - that using a term like "short-tempered dwarf" where a dwarf can hear it is likely to very shortly become a self-fulfilling prophecy.
No, it's all down to a curse placed on the Klatchian Seriph of Al-Ybi by an unfortunately dyslexic deity. This particular Seriph, at least until the curse was lifted, was forced to endure a situation where everything he touched turned to Glod. Glod being a terminally bad-tempered dwarf from somewhere near the Hub, made more so by being magically transported to a desert city on the Circle Sea and magically duplicated a few thousand times... it is said that to this day, the population of one city is unusually short in stature and bad-tempered.
To add to Glod's woes, towards the end of her life, legendary witch Black Aliss made the same sort of elementary spelling mistake when she tried to put the frighteners onto a minor royal family who she felt were not showing her enough respect. She duly cursed the princess into having to spin straw into Glod, which must have led to a vast surplus of short-tempered dwarfs being called into existence within the precincts of that palace. According to the memory of Nanny Ogg, he had to be given a large amount of money to go away and not make a scene. (Witches Abroad).