Walrus
Both the male and female walrus grow tusks. They can use them to protect themselves from polar bears and killer whales and use them when they eat. When they eat bigger preys such as seals and small whales, they first tear them apart with their tusks to make them easier to eat. Another important use of a walrus's tusks is to pull itself out onto the ice. Pushing its tusks into the ice, the walrus gets extra help hauling its huge body out of the sea. This is probably how walruses got their family name Odobenidae, which comes from Greek words meaning "one that walks with teeth". They do not walk with their teeth, but it can look as if they do when they pull themselves out of the water. Their tusks can also be used to cut holes in the ice. Tusks are slightly longer and thicker among males, who use them for fighting, dominance and display; the strongest males with the largest tusks typically dominate social groups. Tusks are also used to form and maintain holes in the ice and aid the walrus in climbing out of water onto ice.