1966 Thor and the Avengers vs Molto, the Lava Man

Mighty Thor TV Series 1966 TV-Y7-FV Mighty Thor (1966)
The contemporary adventures of the Norse god of thunder and lightning.
Creator: Larry Lieber
Stars: Bernard Cowan, Don Mason, Claude Rae
S1.E13 ∙ Molto, the Lava Man 1966 Episode aired 1966 Mighty Thor (1966)
When a race of underground lava men threaten the surface world with destruction, Thor gathers his Avenger teammates in an attempt to thwart the attack. The group is aided by an unlikely ally, their former team member, the Incredible Hulk.
Director: Shamus Culhane
Stars: Bernard Cowan, Don Mason, Jack Creley