The salmon hat craze was first observed in 1987 when a female orca in the Puget Sound area of the northeast Pacific was seen carrying a solitary dead fish on her nose. Within a few weeks the behavior was picked up by members of other pods, suggesting something about it must have appealed.

Though researchers have some best guesses, nobody seems to know for sure why exactly a killer whale in Washington state was wearing a dead fish as a hat.

An especially popular killer whale put a dead fish on his head, in a throwback to a fashion last seen in the 1980s.