The two Achillobators are the main antagonists in The Land Before Time XI: Invasion of the Tinysauruses. Their is voiced by Frank Welker.
They didn't appear until the climax of the film, when the tinysauruses run into them that chase them and find their way into the Great Valley. Later they then lunge at Cera and her friends, causing a chase. Littlefoot shows up just at the right time and saves Ducky just as she was about to get eaten. When all seems lost, the tinysauruses show up and fight the Sharpteeth. The grown-ups of the Great Valley then show up and drive the sharpteeth back into the Mysterious Beyond through a hole. Then they cover up the hole with a large boulder.