Species (Hydrurga leptonyx) of generally solitary earless seal (family Phocidae) found in Antarctic and sub-Antarctic regions. It is the only seal that feeds on penguins, young seals, and other warm-blooded prey. It is slender and has a long head and long three-cusped cheek teeth. Named for its black-spotted gray coat, it attains a maximum length and weight (greater in the female) of about 12 ft (3.5 m) and 840 lbs (380 kg). It has a reputation for ferocity but is not known to make unprovoked attacks on humans.