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.

A resident orca off the coast of Washington state was recently spotted sporting a dead salmon on its head. The phenomenon was first documented in 1987 ...when whales from three separate pods were seen wearing salmon on their heads.

Sometimes, nature surprises us with behavior that feels more like a quirky human trend than an animal instinct. That’s exactly what’s happening off the Pacific Northwest coast, where orcas are once again donning “hats” made from dead salmon.