Fast-moving with sharp teeth, leopard seals eat krill, fish, sea birds, squid, small seals and penguins. The diet of the leopard seal depends on its size.
Smaller leopard seals eat mostly krill, but also consume squid and fish. Larger leopard seals eat king, adelie, rockhopper, gentoo, emperor and chinstrap penguins, along with other seals, including the crabeater seal. Leopard seals are the only species of seal known to consume other species of seal. They have also been known to eat Antarctic fur seal and southern elephant seal pups.
While hunting penguins, the leopard seal patrols the water, almost completely submerged, near the edges of the ice waiting for the bird to enter the water. Once the penguin enters, the leopard seal grabs the bird by the feet and thrashes it against the water repeatedly until it dies. The leopard seal does the same on land, grabbing smaller seals by the tails and thrashing them against the ground to the point of death.
Contrary to some reports, leopard seals do not skin their prey prior to consuming it. They do, however, tear and rip it into smaller pieces first. The leopard seal is second only to the killer whale as Antarctica's top predator. It has 1-inch-long canine teeth.