The human could be a time - traveler. Just like, they might be exploring some ancient caves and stumble upon a time - rift that transports them to the 'Land Before Time'. Their presence would disrupt the natural order at first, but then they could adapt and find their place.
A human could be magically summoned to the 'Land Before Time' world. Maybe there's an ancient spell or power that calls upon a human to come and solve a particular problem in that world. For example, a dark force is threatening the dinosaurs and the magic believes a human's creativity or knowledge can help defeat it.
Perhaps the human is an alien who looks humanoid. Their spaceship crashes in the 'Land Before Time' world. They are different from the dinosaurs but also share some similarities in their struggle for survival. They could then use their advanced technology (even if it's damaged) to help the dinosaurs in various ways, like finding new water sources during a drought.
A human character could be integrated through a magical portal. Maybe there's a hidden gateway on Earth that leads to Thra. Once in Thra, the human's different perspective and skills can start to have an impact. For example, if the human is a good fighter, they could train the Gelflings in new combat techniques.
Incorporate some mystery elements. For instance, the human discovers a strange object in the Land Before Time that seems to have some connection to their own world. They then go on a journey to figure out what it is and how it can help them. This kind of mystery will keep the readers interested and guessing throughout the fanfiction.
Make them have distinct personalities. For example, a human character could be really brave but also a bit clumsy. This would add humor and make their interactions with the dinosaurs more interesting.
One idea could be a human from the modern era somehow getting transported to the Land Before Time world. They could use their knowledge of modern things like first aid to help the dinosaurs when they get injured. For example, when Littlefoot's mother is hurt, the human could try to stop the bleeding with a makeshift bandage.
One idea could be a human explorer getting lost in the prehistoric world of 'Land Before Time'. They could form an unlikely alliance with Littlefoot and his friends, teaching them about human ways while also learning about the dinosaurs' survival skills.
In fanfiction, a human could be a magical being who is sent to the Pride Lands to bring balance. They could interact with the different species, teaching them about things like art or music, which are foreign concepts in their world, and in turn, learn about the values of the animal kingdom like loyalty and courage.
The human could be introduced as a lost traveler who stumbles into the Pride Lands. This way, they are initially an outsider and have to learn the ways of the Lion Guard and the animals.
First, think about the dinosaur species your OC is. Each species has its own characteristics in the 'The Land Before Time' world. For example, if it's a Triceratops, they are known for their strength and loyalty. Then, give your OC a unique personality trait. It could be that they are overly curious, which often gets them into trouble. Also, consider their backstory. Maybe they lost their family at a young age, which shaped who they are today.
Chomper's character could be developed by showing his growth in terms of controlling his natural instincts. For example, in a situation where he is really hungry but has to resist the urge to hunt his friends' kind. This would show his moral strength.
A human could be integrated by being a lost traveler. Maybe they stumbled through a magical portal and ended up in Spyro's world. Then they would have to adapt to the new environment and find ways to communicate with the dragons and other creatures.