The Flintstone Comedy Show

The Hideous Hiss of the Lizard Monster [Pebbles, Dino & Bamm-Bamm] (1x59)

:

Searching for a missing Dino in an abandoned diamond mine, Pebbles and Bamm-Bamm confront a horrifying Lizard Monster. They discover the mine's engineer assumed this disguise to frighten the workers away.