Personality: Ducky the swimmer (a saurolophus) is and always has been very much at the heart of the crew. Though somewhat pliable and quick to go with the flow, she is never halfway about anything; whatever she does, says, or feels, she jumps in with both feet every time. She is also acutely curious and playful, always willing to look into anything new that catches her eyes. Her talkativeness can get rather annoying (in the first movie she's identified as a “bigmouth” rather than a swimmer), but she's as big on courage as anyone you're likely to find despite being the smallest dinosaur among her friends. Also, like Littlefoot, she is outgoing and quick to see potential in others – sometimes to excess, as when she spoke of teaching Chomper to swim in The Great Valley Adventure. Despite being rather pliable in how she reacts to situations, she is a peacemaker at heart and can often be seen trying to stop her friends (particularly Littlefoot and Cera) from fighting one another. Indeed, she hardly ever shows anger herself – so rarely that she once had to go to Cera for advice on how to express the emotion (Land Before Time VIII: The Big Freeze). Ultimately she has a very maternal attitude, despite often acting like the youngest of the group except for Spike.

Ducky often says the same word or phrase more than once (such as, “It did, it did,” or “I do, I do”). She is particularly noted for rattling off “yep yep yep” and “nope nope nope.” She also sometimes uses bad grammar (though less often than Petrie), such as saying “finded” or “scardeded” instead of “found” or “scared.”

Family: Ducky's parents appear to be the only pair (related to the gang) to both make it to the Great Valley alive. They accepted Spike as their adopted son at the end of the first movie, and apparently had a number of young along with Ducky (Ducky later gives the number as thirteen in Secret of Saurus Rock, though the original movie shows only a clutch of six eggs). Another clutch of eggs was featured briefly in The Great Valley Adventure, but neither they nor their occupants appeared in subsequent films. Of Ducky's large family, only her mother ever has any lines to speak of or plays any significant role in the later movies or the series.

Friends: Although she was somewhat pliable and ambivalent in her loyalties in the first movie, since that time Ducky has proven staunchly loyal to the whole group, and to anyone else she befriends. She was the first of the gang to make friends with Littlefoot (in the first movie), has a close bond with spike as her foster-brother, and is often seen working with Petrie – perhaps because of their similar sizes.

Other: Ducky’s species has been the subject of some confusion. In most official merchandise and other material she is identified as a Parasaurolophus, but in The Land Before Time Sing-Along Songs she is said to be a Saurolophus (which she and her parents more closely resemble). Adding to the confusion is a coloring book which describes her as an Anatosaurus.