(Hydrurga leptonyx), generally solitary, earless seal (family Phocidae) that inhabits Antarctic and sub-Antarctic regions. The only seal that feeds on penguins, young seals, and other warm-blooded prey, the leopard seal is a slender animal with a relatively long head and long, three-cusped cheek teeth. It is named for its black-spotted, gray coat, and it attains a maximum length and weight (greater in the female) of about 3.5 metres (12 feet) and 380 kilograms (840 pounds). The leopard seal has a reputation for ferocity but is not known to make unprovoked attacks on man; it is of no commercial importance.