"The Fantastic Four"

Menace of the Mole Men Sat, Sep 9, 1967
The Mole Man, out for revenge, lures the Fantastic Four to a deserted island. The Mole Man has constructed an elaborate tunnel system that can lower major cities of the world beneath the Earth's surface. The villain intends to eliminate the foursome so he can proceed with his plan.

The Fantastic Four is an American animated television series produced by Hanna-Barbera Productions and based on the Marvel Comics superhero team of the same name, aired Saturday mornings on ABC from September 9, 1967, to September 21, 1968.