Enhydriodon is an extinct genus of typically large otters that lived in what is now Kenya, Ethiopia, Uganda, Chad, South Africa, and India from the late Miocene up to early Pleistocene. The otter is thought to be a relative of modern-day sea otters. E. omoensis and E. dikikae are described as the largest mustelids to have ever existed, though only fragments of the genus have been found such as the skull, femur, and dental remains in Ethiopia. Multiple estimates put them at about 200 kilograms (440 lb) while E. omoensis was described to be lion-sized, making them the largest mustelids described so far. Most species of the Enhydriodon genus are presumed to be semi-aquatic given most of the fossil isotope values being similar to fossilized semi-aquatic animals like hippopotamuses. The largest