Sidney The Sloth, better known as Sid, is the deuteragonist of the Ice Age series. He is a Megalonyx who is Manny and Diego's best friend and one of Peaches' adoptive uncles. He is the tritagonist of Ice Age and Ice Age: The Meltdown, the main protagonist of Ice Age: Dawn of the Dinosaurs and the Easter Special, the deuteragonist of the Christmas Special, a major character in Ice Age: Continental Drift and the tetartagonist of Ice Age: Collision Course.