Three women who presumably had been enjoying a nice swim in the tropics are fast becoming famous for their change of expression–to one of collective dread–after a large stingray launched onto their backs. (Actually, if you look closely, there appears to be a man lifting the creature onto their backs for a clearly successful “photobomb” prank.)

The image, source unknown, reportedly was captured at a Cayman Islands tourist spot known as Stingray City, where swimmers can feed the rays pieces of squid.

Stingray City Trips states on its website: “The Stingray City Sandbar is a fun place and is suitable for everyone. You may be surrounded by more than two dozen ‘tame’ Atlantic Southern Stingrays that enjoy the company of humans.”

The photo, since surfacing Wednesday, has appeared on Twitter and numerous Facebook pages, and has been retweeted and shared thousands of times. It also has appeared on Reddit, Gawker and Buzz Feed, to name just a few websites.

As for the women, they’ve likely gotten over the clammy experience, but may not be so trusting the next time they’re surrounded by human pranksters.