Sidney, known more commonly as Sid, is a ground sloth who is part of a herd of different animals after a number of adventures and experiences brought them all together. Born into a family of sloths that went on to abandon him well into his adulthood, Sid met a mammoth named Manny and a saber-tooth tiger named Diego as the three of them made a journey through a tundra to return a human baby named Roshan to his tribe. Following the journey, the three animals remained the best of friends, forming their own "Herd".