A mysterious 'alien' creature with a transparent head and 13 legs has been spotted at the bottom of the ocean by a baffled deep-sea diver.
The strange animal appeared to sport a large jelly-like ball where its head should be, that seemed to be filled with spiky teeth.
Its legs, with a similar aesthetic to tentacles, stretched perpendicular to its long straight body, which also appeared to be covered in small suckers.
The incredible footage of the odd sea creature was filmed by a diver in Bali, who did not appear to have any idea what the alien-like fish could be.
But while it might have looked like it's from another planet, the creature is actually a sea slug - also known as Melibe viridis.
Sea slugs can grow to over 12cm in length, but their most fascinating attribute is the way they feed.
According to Sea Slug Forum , the creatures use their transparent heads as an 'oral veil' - or fishing net - to catch their prey.
When another sea creature touches the sensitive cells on the inside of the veil, it will contract rapidly, trapping the prey.
After the sea slug's meal has been captured, it is then slowly ingested.
Unsurprisingly, viewers were also confused by the creature and it didn't take long before they were speculating over what on earth it could be.
One man wrote: "I dunno, but I reckon if you threw it at a window it would stick."
But another viewer was much more convinced: "This is a sea slug."