Diego is the tritagonist of the Ice Age series. He is a smilodon who is Manny and Sid's best friend and one of Peaches' adoptive uncles. He becomes Shira's husband. He is the (former) secondary antagonist turned deuteragonist of Ice Age, the tetartagonist of Ice Age: The Meltdown and Ice Age: Continental Drift, a major character in Ice Age: Dawn of the Dinosaurs, Ice Age: Collision Course, and the Christmas Special, and the tritagonist of the Easter Special.