These 2 Sharpteeth (Utahraptor) appear during the climax of The Land Before Time XI: Invasion of the Tinysauruses as the main antagonists. They are Fast Biters, a term used by the characters for the dromaeosaurs.
They first appear when the Tinysaurus herd step out of a cave into the desolate areas of the Mysterious Beyond. Shortly afterwards, the raptors attack the group, chasing them into the cave. The pair get stuck, and the Tinysaurs hide. The pair free themselves put did not notice the Tinysaurs hiding nearby. They continue to move in the same direction.
Soon, the Fast Biters head to the Great Valley by getting through a hole in a large pile of rocks that were put there to drive the Tinysauruses out from the valley. The Utahraptors then scurry into the brush. Littlefoot's friends, mistaking the rustling of the foliage for their friend, head towards the bushes, only for the two predators to jump out.
A chase ensues, with Cera only surviving thanks to Tria, who headbutts the attacking blue sharptooth aside and aids the children in their spat against the predators. Littlefoot also helps out Ducky by pulling back a tree branch and letting go, knocking over the purple sharptooth that was chasing her, but it quickly recovers and chases both of them. Later, Spike and Petrie are nearly eaten by the blue sharptooth, before Lizzie and Skitter start tickling the fast biter.
Meanwhile, the purple sharptooth charges at Tria, but then Daddy Topps shows up to help. It charges at him and he lifts the fast biter into the air. Later, the blue sharptooth fights off Lizzie and Skitter after biting its own tail. Petrie and Spike try to protect the two Tinysaurs from both of the sharpteeth, but then the entire Tinysaurus herd comes to help. They climb the raptors, biting them.
Soon both Fast Biters collide, however, knocking the Tinysauruses down. The raptors try to kill the scattering Tinysaurs but Topsy runs over to protect them. The sharpteeth split off and circle around him to attack his sides, but they are then scared off by the appearance of the rest of the Great Valley's population. The raptors flee back to the cave leading back to the Mysterious Beyond, with the blue one stopping to snarl at the flatteeth before finally retreating.
- Even though these particular characters haven't been seen since XI, many other Utahraptor appear throughout the rest of the series, most prominently in the television series, wherein two Utahraptor, Screech and Thud, serve as subordinates for the main antagonist of the show, Red Claw.
- Other than being voiced by Frank Welker, the Utahraptor's sound effects consist of both jaguar and elephant sounds. It should be noted that if you pitch up the Fast Biter's unique sounds the famous Fay Wray scream from King Kong (1933) can be heard. This makes them the first of many Sharpteeth to be voiced by a female actress.
- The blue Fast Biter looks exactly the same as the Sharptooth Mom from The Great Egg Adventure. It may even be the Sharptooth Mom, which would mean that the blue sharptooth is female.
- It also bears a striking resemblance to Screech, though the XI fast biter has red eyes, while Screech has yellow.