Leedsichthys is the largest fish ever. It is so big that it ate the smallest creatures in the world. It was a filter feeder, that means it ate zooloplankton. It would release eggs in the water and the baby fish would grow in mass in one year. Small predators such as sharks would eat the flesh off of these giants without killing them. Making the only creature of the time to kill this peaceful swimmer was the large pliosaur Liopleurodon. The dead body of Leedsichthys can feed many scavengers such as the crocodillian Metriothynchus for days.