Underground dinosaur cave crystal

The underground dinosaur cave crystal appears in the underground dinosaur cave beneath the crust of Earth in the 1987-1996 series. It is located atop a tall mountain, and is the source of lifeforms surviving inside the cave.

Krang and Shredder try to use its powers to repower the Technodrome, by taking it and bringing it into Krang's mobile fortress. At the end, the turtles and April O'Neil stop them.