When you read this entry's title, you probably pictured one of those goofy-looking hats we so often make children wear. You know, one of those animal-themed hats that look like a chicken is roosting on Tommy's head or a shark is in the process of munching little Cindy.
But nope. This is a hat for adults:
A hat for adults that just happens to be decorated with fins (or is the technical word here "plates"?) across the front.
(Note: This piece is also known, among some circles, as the Lisa Simpson Hair Hat.)