Defenders of the Earth S01E65 - The Thunderlizards of Ming

The Defenders fly to Alaska and discover that a long-dormant volcano, with an artificial dome placed over it, is mysteriously heating up. After a narrow escape in a mountain cave, the group that discovers that Ming has used a drill to thaw out tens of thousands of beasts buried in the frozen tundra, and intends to release them all over Earth so that they can destroy all the world's cities!