Like all the other members of Gutt's crew, Shira was once in danger for her life when Gutt rescued her from an unknown fate. This earned Gutt her loyalty.
Shira defected from Gutt when she met another saber named Diego, who convinced her to leave the crew and join the herd of animals that he was a part of. Realizing unlike Gutt, the herd would look out for her, Shira renounced her position as a pirate, and joined the herd.
Shira had once been part of a saber-tooth cat pack but decided to leave them behind, to make a life of her own and to don't let herself depend on anyone, a decision that was hard for her to accept. At one point, Shira was found by Gutt, an ape that had taken to the seas aboard a great ship fashioned from an iceberg: Gutt had saved her life and she joined him as first mate.
The Herd's capture
Gutt made his presence known to the castaways, stating that they were lucky to have been found by Gutt and his crew. Manny informed the ape that they only wanted to return to the continent, which Gutt mocked, and informed Manny that there was no way back. With that, Gutt ordered his crew to attack the ice floe, taking the castaways as captives. Shira leaped from the ship and stopped Diego, who was cutting the mooring lines that tethered the ice float to the ship. Shira stopped him before he could cut the last one, keeping it under her paw. Diego, keeping his pride, declared that he doesn't fight girls. Shira took advantage of this and let the line go, slapping Diego in the face, at which point she pounced on him and pinned him down while laughing slightly and then saying "I can see why." Then Diego, like the others aboard the ice floe, was brought aboard Gutt's ship.
The herd were brought on to Gutt's ship and tied up. Gutt, through the use of song, attempted to convince Manny and his friends to join the crew. When he was refused, Gutt decreed that they be made to walk the plank.
Manny and Diego managed to escape their bonds, but the ensuing battle between Manny and Gutt accidentally caused the collapse of Gutt's ship. Gutt and most of his crew escaped, but Shira was left behind. Though on the verge of drowning, she refused the herd's help. After Manny brought her on to their makeshift raft, Diego asked if she would like to join their "scurvy crew." Shira mocked the idea, calling the group a joke. Diego responded by calling her "kitty", which angered her into pouncing on him, which he quickly reversed. Granny’s comment of puking if they kissed, caused Diego to get off her.
The herd managed to find their way to Switch-back Cove. As soon as they hit shore, Shira attempted to escape, but was stopped by Diego, who discovered that Gutt was at the cove also. Shira was imprisoned within a tree to prevent another escape attempt. Diego came to her during the night with some water. Shira refused at first but decided to take it when Diego pointed out she would dehydrate without it. They then discussed their pasts, and Diego compared Gutt to the herd, implying that Gutt didn't care about Shira. Nevertheless, Shira remained adamant in her beliefs.
Change of heart
Shortly afterwards, when Gutt held Manny's family hostage, Shira was seen struggling to get up, suggesting she had tried to stop Gutt, but failed. During the battle, Shira attempted to free Ellie, but was waylaid by Squint, and knocked aside by Dobson. Following Gutt's defeat, Shira asked Diego if he still wanted her on their "scurvy crew", to which Diego replied in the positive, welcoming her to the herd. Shira and the rest of the herd traveled to a new home soon after.
Manny and Ellie's Anniversary
One day, Shira was chasing a gazelle. She chased the gazelle passed her mate and growled when the gazelle asked her to please not eat him. Later, Shira and Diego went to Manny and Ellie's anniversary party. They ate some berries and talked about having their own kids. A Young Start and Young Aardvark stumbled upon Diego and Shira and saw the berry juice dripping down their chin. Thinking it was blood, the kids ran away in fright. Shira was puzzled and told Diego that she even smiled. Later, there was a meteor shower and an asteroid approaching. They hid in an Ice Cave until they thought it was safe.
An old friend of the herd, a weasel named Buck, came back from the Underground Dinosaur World and greeted Shira by salsa dancing with her. Buck led the herd through a forest where an electrical storm hit. Shira stopped when she noticed her fur by her paw becoming fuzzy from static. They safely made it out and Buck went in and saved a baby pumpkin, which he called Bronwyn. The herd thought it was strange. They stopped for the night and in the morning they found that Granny was missing. They heard her yelling and followed it.
They found that Granny was getting massages from a prehistoric rabbit called Teddy. They were in Geotopia, a land of crystals and where everyone stayed in their youth. Brooke, a sloth, fell in love with Sid and called her squad of Minicorns called Bubbles and Misty. They tapped their hooves on the crystal floor, releasing a crystal hoverboard, which took them to the Geotopian master, Shangri Llama. Sid broke the Geotopian wall and the Geotopians agreed to give up their crystals to save their lives. The crystals were put in a volcano, which moved the asteroid elsewhere. It worked, and they celebrated their victory.
Personality and traits
At first seeming gruff and cold, Shira was loyal to those that helped her: Gutt had once made her his first mate, a position which, despite Gutt's indifference at her loss, she initially held close. Shira was not easily swayed in her resolve and could often be quick to anger when she dealt with those that caused her trouble. Despite her anger, Shira did fall in love with Diego, who introduced her to a better way of life than piracy: being part of a herd. Herd life was initially something that Shira was uninterested in, due to her snide, sardonic persona, which deemed individuals like Diego, who had turned down his former rough-and-tumble life in a saber pack, as soft and weak; this view changed quickly as she was accepted into Diego's collective herd. Shira is competitive and knows what she wants. When she was being chased by Diego on Switchback Cove, she ended up in a dead end. When Diego thought she was trapped, she revealed she had the ability to climb steep hills and rocky areas. This is an ability that most sabers possibly don't have. Near the end of the film she is shown to be quite affectionate towards Diego, given they’ve become a couple. She is seen leaning on his shoulder when the herd sailed away to a new home, as well as nuzzling his side in the credits.
Shira, as a saber-tooth cat, sported the same features that other sabers had: short, compact build with powerful running legs, clawed paws, short tail and ears, and a pair of fangs that were shorter than Diego's and not as sharp. Shira was grayish in hue, almost sliver, unlike other sabers, which tended to be dark tan or orange: Shira's pelt was striped somewhat with dark grey stripes and her eyes were vivid teal. Shira wore two earrings on her right ear, fashioned from an unknown substance, one being small and blue, the other, larger and green.
Behind the scenes
Shira was voiced by actress and singer Jennifer Lopez.
Shira was initially supposed to have orange-red fur like most sabers of the franchise, but the directors decided to have her appearance stand out with a different fur color, to keep viewers from mistaking which saber was Diego and which one was Shira at wide screen shots. You can see a picture of Shira's early design in the Shira/Gallery.