Behemotops are mammals confirmed to appear in Additional Creatures: Aquaria.
Behemotops, named after the Behemoth of Hebrew legend, is a species of desmostylian that lived along the Pacific coast during the Oligocene Epoch, from 36 to 25 million years ago. Behemotops is the earliest known of the desmostylians, a group of marine mammals which did not persist into the present day, and their relation to other mammal groups is unknown. Desmostylus is another desmostylian. They were herbivores, feeding on sea grasses. Behemotops in particular has elephantine features, which might hint towards desmostylians being an aquatic offshoot of the elephants, similar to sirenians.
Behemotops in Additional Creatures is planned to be an aquatic combat creature, akin to spinosaurus, but more focused on aquatic movement and tanking. It's design is intended to be aggressive-looking, with its jaws looking akin to a hippo. It's tusks are based off of the Oni of Japanese legend.