In 1996, he tried to sell a substance that he claimed was powdered dragon claw to students studying for their O.W.L.s. In truth, the substance was dried Doxy droppings, which Hermione Granger confiscated as a school Prefect. Harold later offered to sell Firewhiskey to Dean Thomas and Seamus Finnigan.
- The name "Harold" is from the Old English name Hereweald meaning "leader of the army", derived from the elements here "army" and weald "leader, ruler". The Old Norse cognate Haraldr was also common among Scandinavian settlers in England. This was the name of five kings of Norway and three kings of Denmark. It was also borne by two kings of England, both of whom were from mixed Scandinavian and Anglo-Saxon backgrounds, including Harold II who lost the Battle of Hastings (and was killed in it), which led to the Norman conquest. After the conquest the name died out, but it was eventually revived in the 19th century.
- A "dingle" is a small wooded valley; a dell.
- Harry Potter and the Order of the Phoenix (First mentioned)