"Sharptooth Flyer" is a term used in The Land Before Time series for any carnivorous animals that are capable of powered flight, namely toothed pterosaurs.
Relatively few Sharptooth Flyers have appeared in The Land Before Time franchise. The first instance of one appearing is in The Land Before Time IV: Journey through the Mists, where Ichy; a predatory bird, the only named Sharptooth Flyer and the only one known to be capable of speech; is one of the two main antagonists. The film uses a unique term, "Sharp Beak", to refer to Ichy.
Another Sharptooth Flyer appears in The Land Before Time V: The Mysterious Island; when Ducky falls off a cliff, a predatory pterosaur catches her with the intent of feeding her to her babies. One of the babies tries to bite her, but Ducky moves and it bites its mother's foot. She screeches and drops Ducky out of the nest.
Two imaginary Sharptooth Flyers also appear in the TV series in the episode "The Spooky Nighttime Adventure", where Petrie tells a story that his uncle told him about a gigantic flyer swallowing Sharpteeth whole. Another, more stylistic Sharptooth Flyer appears Cera's dream later in the episode.