Blue Umbrella Hat

There is a specific kind of person who will genuinely wear this, and they will get more use out of it than anyone expects — fishing, festivals, gardening, queueing for anything outdoors in British weather. For everyone else it's a gag gift, and it works as one because it's unambiguous. No explanation, no reference to get: it's an umbrella you wear on your head, and your hands are free. That's the whole idea and it doesn't need more. One-size headwear is also one of the very few clothing items you can safely give someone whose sizes you don't know, which makes it more giftable than it first appears.