As if a single-headed shark isn't scary enough, researchers at the University of Malaga were casually just sifting through a bunch of sawtail catshark embryos and, surprise, a rare, two-headed embryo was part of the fray.
According to DailyStar, the biologists discovered the creature growing in a translucent egg, detailing the freaky find in the Journal of Fish Biology.
"Each head had a mouth, two eyes, a brain, a notochord [like a spinal cord] and five gill openings on each side."
They added that in each body there “were two hearts, two oesophaguses, two stomachs, two livers.”
So, yeah, this was a once-in-a-lifetime find.
While the embryo won't have the chance to reach the state of growing much bigger—instead, being kept in the lab—the two-headed shark probably wouldn't have been able to survive in the wild anyway, according to Michelle Heupel, a researcher at the Australian Institute of Marine Science, per Daily Star.
“Survival after birth may occur, but would likely be very brief.
“It is unclear whether the two heads will preclude swimming and prey capture, and whether joined internal organs will function adequately.”
An Australian sawtail catshark tends to be no bigger than about two feet, and is generally slim in nature. So, while it wouldn't have been much of a threat to scaring humans, there's no denying that it would have haunted our nightmares had this been seen underwater.