ugg boots
I was given a pair of sheepskin boots made by a company which included ugg boots in its name and which boasted that it was established in 1933. This seemed tremendously exciting (for an Aussie lexicographer at least) as it suggested a very early citation for ugg boot, but It turns out that the business name was changed to include ugg boots in 1991.
The mystery of the origin of ugg boots has never been solved. Both Macquarie Dictionary and the Australian National Dictionary lean towards the shortened form of ugly boots, but a TROVE search on ‘ugly boots’ just turns up boots which are ugly.
The OED still gives the origin as a cartoon character called Ugh. If this were true then it is unlikely that the variations ug and ugg would have appeared. The word ugh as a representation of an inarticulate grunt, later becoming an exclamation of disgust, goes back in British English to the middle of the 1700s. Why would we suddenly become doubtful about the spelling, particularly if that spelling was reinforced by a cartoon?
It is sad that TROVE cannot shed any more light on this, but the origin probably lies in the spoken language of surfers in Adelaide which is where the earliest citations appear. The boots were handmade from bits of sheepskin long before they appeared in an Adelaide shoe shop, and long before they became a fashion item. It is difficult, therefore, to trace the formation of the name.