What does a pocket shark carry in its pockets? Nobody knows. Only one of the pint-sized fish has ever been found—until now.

Surprised scientists found this little guy stowed at the bottom of a freezer. He has been waiting there since 2010, when government officials found him in the Gulf of Mexico. He measures about 5.5 inches long. He has two pockets next to his front fins.

The first pocket shark—a female—was found 36 years ago near Peru. Now it sits in a Russian museum. Why did God give these creatures pockets? To hold babies like kangaroos? Scientists don’t think so. They think the pockets may be used to secrete glowing fluid.