Hyp's Dad is a Hypsilophodon and the father of Hyp. He and his son first appeared in The Land Before Time III: The Time of the Great Giving. He is usually grumpy and his treatment of Hyp is heavily implied to be the cause of Hyp's behavior.
For most of the movie, Hyp's Dad is unseen, and only makes a major appearance at the end. However, from that appearance, it is rather obvious the reason Hyp has been treating the others so poorly is due to his father's attitude. He is seen when Hyp knocks Nod into the water and Daddy Topps thinks Littlefoot did it. He later apologizes to Littlefoot's Grandpa and Grandma over his son's actions and leading Daddy Topps to insult Littlefoot.
Later in the film he has a much bigger role. When the adults find the children in the Mysterious Beyond, upon learning Hyp was the one who wandered off and the others had come to rescue him, he scolds him for it. He respectfully leads Littlefoot and the others away from Hyp. Daddy Topps, hearing this, realizes that yelling at their children causes them to act negatively to others, with he himself yelling at Cera. Upon telling her of this, Hyp's Dad sees the error of his ways. However, a pack of Velociraptors then attack, and while the adults fight them, Hyp's Dad leads the kids to safety. However, the raptors, realizing they can't beat the adults go after the children. This results in a fight on a small cliff, and both the adults and the raptors fall.
Hyp distracts the raptors when they wake up, and Hyp then comes and insults the raptors to get their attention. As the raptors chase Hyp, the adults wake up. Outnumbered, the raptors once again chase the children but the children bury them with rocks. They get out, and just as the raptors and adults are going to fight with even the children wanting to join, the rocks that had covered the water had been knocked off, causing it to wash away the raptors. After the water is returned, Hyp and his father reconcile.