A River Otter. An Otter is a type of a mammal. One swims into the river and another into the sea. Transformers With That Beast ModeEdit Otterbot Infamy GalleryEdit A Sea Otter. Sea Otter swimming.1 of 2Add photo Retrieved from "https://beastwarstransformers.fandom.com/wiki/Otter?oldid=38580" Categories: Animals Mammals Otters Community content is available under CC-BY-SA unless otherwise noted.