At first Mulberry thinks it is a giant fish, carrying another, smaller fish between it’s sharp needle-like teeth. However as more and more of it moves back onto the beach she realizes with a thrill that it is a pony, or at least pony shaped. It’s head is that of a predator fish, and reminds the mare of something akin to a piranha. Below that it’s body is scaled, and a long ridge runs from the head all the way back to the tail, which is far more fish-like than pony. At the ends are more fins, as well as long, sharp claws.
As the creature gets up to the barrels the mare notices the monster is dragging a net with it. It spits the fish in it’s mouth into the barrel, and then empties the net into the barrel. After that it walks back into the water.