Elsa is one of the supporting protagonists in the movie, We're Back! A Dinosaur's Story. She is a feisty purple Pterodactyl and is voiced by Felicity Kendal.
Just like her fellow dinosaur friends, Elsa was retrieved by Captain Neweyes' time machine aircraft and fed Brain Grain cereal, becoming intelligent and friendly in the process. She is first seen eating some hot dogs with her friends, Woog the Triceratops and Dweeb the Parasaurolophus, when Rex the Tyrannosaurus Rex, another dinosaur fed Brain Grain, shows up and introduces himself. Elsa politely greets Rex, telling him she is delighted and enchanted to make his acquaintance. She also reveals that she once laid an egg after Woog spilled the beans about it, making her initially angry, but then admits that she did and was embarrassed about it.
After the hot dog lunch, Elsa and the other dinosaurs meet Captain Neweyes. Neweyes explains that he fed the dinosaurs Brain Grain cereal so that he could grant children's wishes related to seeing dinosaurs in the middle future. After seeing how many children want to see real dinosaurs, Elsa and the others are amazed and agree to go with Neweyes' request.
They travel to the middle future and are dropped off at the Hudson River after being told to find Dr. Bleeb and the Museum of Natural History of New York City. While admiring the beautiful city, they meet Louie, a boy who's running away to join a circus. They agree to accompany him as he goes to the circus. When Rex falls into the river and nearly drowns, Louie uses a crane to help pull him back onto land. Elsa and the other dinosaurs help by keeping the crane from falling into the water. Rex is rescued, to everyone's relief, and they all venture into the city.
While hiding in an alley to avoid being spotted, Louie takes flight on Elsa to find a way to get to Central Park. Before doing so, Louie mistakes Elsa for a bat, much to her anger and states that she's a Pterodactyl. Louie then asks Elsa if she can fly, to which she chuckles in response. During their flight, Elsa makes fast and dangerous maneuvers, which scares Louie enough to scream, "Get me off of this thing!" They eventually land near a clothing store, where they hear a young girl crying. Louie walks up to the girl, who reveals her name is Cecilia Nuthatch. As Louie tries to cheer Cecilia up, Elsa admires them behind the store window, causing Louie to tell her to back off because she's fogging the glass. After Louie convinces Cecilia to come along with him and Elsa and meet the other dinosaurs, Cecilia agrees. Louie and Elsa eventually return with their new friend, Cecilia. After introducing themselves, they all join the Macy's Thanksgiving Day Parade, acting like robots so they could reach Central Park with ease. However, during the parade, Rex starts singing "Roll Back the Rock to the Dawn of Time" after hearing numerous children wish to see a real dinosaur. The song catches the audience's attention and they dance with Rex. Elsa and the other dinosaurs worry, but nothing seems to go wrong until the crowd eventually discovers that Rex, along with Woog, Elsa and Dweeb, are real dinosaurs. As the crowd flees, Louie and Cecilia are separated from the dinosaurs, but tell them to get to Central Park, where they'll meet up with them. But things get worse for the dinosaurs when they discover that Professor Screweyes, Neweyes' evil brother who was told to be avoided, has set up his circus in Central Park. Before they can find the kids, the dinosaurs are chased by the police and authorities. While fleeing, Elsa takes flight and manages to escape from some cops chasing her in helicopters. She eventually meets up with Woog and Dweeb on a motorcycle and they reunite with Rex.
After losing the cops, Elsa and the other dinosaurs go to Screweyes' circus to save their friends, but are too late, for Louie and Cecilia have joined the circus after signing a contract in their own blood. However, Screweyes strikes a deal with the dinosaurs; if they take his Brain Drain pills and revert to their wild selves, he will let the kids go, otherwise, he will keep them for his show. Elsa angrily agrees, calling him a loathsome creature, and the other dinosaurs also agree. As a result, Elsa is reverted into her wild form once again.
At the night of the show, Elsa and the other dinosaurs are chained and can only watch as Rex tries to attack Screweyes. But with Louie's help, Rex spares Screweyes' life and becomes his friendly self again. Elsa becomes her friendly self again when Cecilia hugs her. Woog and Dweeb also become friendly as Neweyes appears to take the dinosaurs and kids home. Elsa mentions to Rex that the way he looks at her in admiration makes her want to lay an egg, causing Rex to chuckle.
The following morning, at the Museum of Natural History, Elsa is the second to introduce herself to the visiting kids. She and the other dinosaurs look upon the excited kids with happy faces as they talk and have fun with them.