Rinkus and Sierra

Rinkus and Sierra are two flying pteradoctyls who appeared as true antagonists in the animated movie, The Land Before Time VII: The Stone of Cold Fire.

Sierra is voiced by Jim Cummings and Rinkus is voiced by Rob Paulsen.

About Rinkus and Sierra
Rinkus and Sierra are Pterano's henchmen, but are much more evil than he, and are often referred to as "devil-like".

Together they set out to find the Stone of Cold Fire so they could use its power to rule the world.

They took Ducky away with them, and chased after her as she tried to escape due to a distraction by Rinkus standing on the edge of a cliff and falling.

She fell through the floor and was thought to be dead, but in violation of Pterano's orders, Sierra took her again when he found out she survived. She bit him, however, causing him to drop her. When Pterano tried to stop them from chasing after Littlefoot and his friends, they grabbed him and forced him to go with them, but they crashed into a rock wall.

Pterano reminded Rinkus and Sierra that he was the leader, but due to a thunderstorm they were forced to camp in a hollow cavelike area on the mountainside. Sierra expressed a desire to feed the kids to sharpteeth, to which Pterano decided to ditch them. Sierra wanted to kill him for this, but Rinkus convinced him to instead let him lead them to the stone. They tricked Pterano into thinking that they were on his side until he tried to take the Stone's power and found it to be an ordinary rock. Rinkus and Sierra threw Pterano to the ground and hit the Stone with rocks, demanding to see its power. At that moment, the volcano that the Stone was on began to erupt. Everyone escaped except Rinkus and Sierra, who were still attacking the Stone, until the Stone exploded, sending them flying through the air where they landed in the same area they had previously camped in, severely burned. It is believed by many that this killed them, but they have turned up alive in fanfiction, and at one point the film makers considered putting Sierra in a sequel (but didn't), so their final fate is currently up for debate.

Personalities
Sierra is the aggressive one and is viewed as a psychopath, while Rinkus initially appears as the stupider one, but is actually more cunning than Sierra, as shown by his plan for Pterano to lead them to the stone so they can take its power themselves.

Trivia

 * Interestingly enough, Internet Movie Database incorrectly listed Sierra as appearing in yet another sequel, Journey to Big Water.