But this mysterious creature from the deep has now been identified as the world’s first documented case of conjoined whale twins.
The remains of the grey whale calves, washed up off the coast of Mexico, were probably stillborn, experts reckon.The carcass was only 2.1m (7ft) long – grey whales are double that length when born.
Alisa Schulman-Janiger, whale researcher at the American Cetacean Society, said: ‘There is no way that conjoined twin whales can survive.
‘Poor little ones. It is also unclear if the mom survived.’