Elephant seals are marine mammals. These seals are the largest seals in the world. A male normally weighs five to six times as much as the female. Although the male is big, do not think the female is small because it can weigh up to one ton. The males can be up to twenty feet in length. All of these seals have the coloring of dark brown to light gray. Most of the time they like to spend time in really big groups and slide along the rocks. This group is called a colony. The elephant seal is a very social marine mammal.