THIS CRITTER IS KILLLING ME. It's a sea slug that has converged on a fish shape.
Here's a vid of it swimming https://vimeo.com/159589650
It's "pectoral fins" are Rhinophores, basically antenna for smelling. It hunts jellyfish, and uses the remnant of its Foot to stick to them.
@codeawayhaley Leviathan? like? from the bible?
@Daylight Livyatan melvillei
@Daylight It was named after Leviathan from the bible, it was a sperm whale around when Meglodon was which likely fed on meglodon if meglodon didn't eat them first.