Gary Clegg credits himself with creating the first commercially successful sleeved blanket. He called it the Slanket (SL from sleeve and anket from Blanket). He sort of backed into the idea while an undergrad at the University of Maine. He was attempting to keep warm in his drafty dorm room with a blanket while watching late night TV, He punched holes in the blanket to help him hold snacks and his remote but then had no way of keeping his arms warm. So with some crude designs, he took them to his mother who then sewed the first slanket. It was actually several months later, and with the urging of a brother, that he began trying to market his creation. After giving several away to friends as gifts, he used borrowed money and hit the trade show circuit. He got a big boost when the QVC shopping channel picked up the slanket and put it in front of millions.
But shoppers weren't the only ones viewing the slanket. So was AllStar Marketing which had already created a cottage industry with similar creations like the Magic Mesh screen and the Topsy Turvy indoor tomato plant. They soon rolled out their own version of the slanket which they called the Snuggie (a play on the word 'snuggle'). The cheaply priced Snuggie infuriated Clegg who contemplated suing but realized he had no real basis since he had already been informed by legal brights that trying to patent a blanket with sleeves was an 'uphill climb to the bottom'. That left the door open to copycats.
But even Clegg's claim to have been the first out the sleeved blanket block was challenged by Sean and Jennifer Ianuzzi. They claimed their 'Freedom Blanket' was first and then brazenly accused Clegg of actually buying one of their creations! They were able to sell several thousand largely through word of mouth but didn't have the deep pockets to do any aggressive marketing. But one former seminary student claimed to have trumped all of them.
In 1990 while an undergrad at Kentucky's Asbury University, Dr Scott McQuate came up with what he called a 'book blanket' which he created with the help of his grandmother to keep warm while reading. He, like, Clegg, attempted to secure a patent but was also told it just wasn't possible. So he matriculated to seminary and put his creation on the shelf (a Swedish woman, Inger Larssen is marketing a 'book blanket' largely through the internet).
AllStar marketing, meanwhile, has never admitted being the first at all though it is arguable that they could claim to be the most successful. In fact, as of the close of the 20th century, some 20 million Snuggies had been sold.