The film's animators opted to make Elliott look more like an oriental, rather than occidental, dragon because oriental ones are usually associated with good. The film is the first involving animation in which none of the Nine Old Men (Disney's original team of animators) were involved. One technique used in the film involved compositing, whereby up to three scenes might be composited together - for example, a live foreground, a live background, and an animated middle ground containing Elliott. Ken Anderson, who created him, explained that he thought it would be appropriate to make him "a little paunchy" and not always particularly graceful when it comes to flying. Don Hahn, who was assistant director to Don Bluth on this film, gained some experience working with a combination of live-action and animation before later going on to work on Who Framed Roger Rabbit.
Elliott is a dragon with the ability to become invisible. He is depicted as a benevolent character who assists children in need, like Pete. He is shown to be fairly clumsy, even when flying. He is also shown to be very protective of Pete.
Elliott is apparently a guardian of children, coming and going, seeking those who are in need of a friend, at least until they have a family who can be there for them or helps those he befriends until their problems are all resolved. Once a child has no further need of him, he sadly moves on and never sees them again, so it's possible he is really a guardian spirit whose purpose is to protect and help children.
Elliott can be a bit of a mischief-maker intentionally or not, as he caused various instances of property damage, and Pete was blamed due to him being invisible -- although he never means any real harm to anyone.
Elliott is initially shown as an unseen force that prevents the abusive Gogans from capturing Pete, who is running away from them. His true form is revealed the next morning, when they have breakfast. He invisibly follows Pete into the town of Passamaquoddy, where his clumsy antics cause Pete to be labeled as a source of bad luck. Elliott reveals himself to Lampie, the lighthouse keeper, before he and Pete escape to a seaside cave.
When Pete is taken in by Nora, Lampie's daughter, Elliott remains invisible, leading her to believe he is merely an imaginary friend. He later accompanies Pete to school, causing more antics. This leads to Dr. Terminus, a medical showman, plotting to capture him, as dragons supposedly have many medical uses.
At some point, Elliott locates Paul, Nora's lost boyfriend, though she fails to believe it at the time. The night that Paul plans to return home, Elliott is captured by Dr. Terminus, while Pete is done so by the Gogans. Elliott is able to free himself and Pete and they return home to the lighthouse. By this time, a storm has broken out, causing the light to go out. Despite being cramped in the narrow staircase, Elliott uses his fire breath to relight it, revealing himself to Nora and Lampie.
The next morning, Elliott is praised for his help, while Nora is reunited with Paul. Pete is given a safe home with them. This leads Elliott to leave in search of another child to help. After saying goodbye to Pete, he flies away.
Elliott makes a cameo in the Who Framed Roger Rabbit Special Edition DVD on one of the menus, but does not appear in the film itself.
Elliott was a common audience member at the club. In the episode "Ask Von Drake", he asked Ludwig what kind of day it was, and he replied by saying, "It's a brazzle-dazzle day, of course!" In "Mickey and Minnie's Big Vacation", he, along with Dragon Maleficent, Mushu, Madam Mim, and the Reluctant Dragon, caused a fire on the stage.
Elliott has appeared alongside Pete in almost every version of the Main Street Electrical Parade.
Elliott also makes a brief cameo appearance in the Drawn to Animation presentation inside The Magic of Disney Animation at Disney's Hollywood Studios, where he is seen in a photograph with Mushu, who refers to him as his cousin.
Elliott makes an appearance in Disney INFINITY as a cameo. In the 3DS version, he would change all the adventures on the game board to Power Adventures.