Diego

Diego is a smilodon (commonly known as a "saber-toothed tiger"), the most distinctive characteristics are his long canine teeth, locks of hair as sideburns and a short tail. He also has a peculiar straight line of hair in his back that is darker than the rest of his fur. In Ice Age, Diego is first shown as being the sinister and serious type, but he softens as he travels with Manny and Sid to return a baby to his human tribe. He also has a playful side, harassing Sid for fun and actually enjoying sliding in the ice cavern. By the end of the movie, Diego bonds with Manny and Sid and joins them in their immigration to the south. In the second film, Diego is less hostile, showing a calm, cool-acting personality; but he hides his fear of water, which Sid finds out about. The sloth teaches Diego how to swim, an ability the tiger later used to rescue Crash and Eddie, the twin opossum "brothers" of the mammoth Ellie. At the beginning of the third film, Diego is experiencing poor physical performance, being unable to hunt down a gazelle. In a conversation with Manny, Diego decides to leave the herd as he thinks that hanging out with them has caused him to go soft. However, when Sid is being taken by a T-Rex dinosaur, Diego joins the herd in the underground Dinosaur World in order to rescue him. Near the end of the movie, he helps Ellie deliver her baby, and even sheds a tear when Peaches is born. He later informs Manny that he has decided to stay with the herd, since he's realized that all the adventure he could ever want is with them.