G.I. Joe: A Real American Hero (1983)

Season 2: Episode 28

Cobra Commander tries to communicate with the creature in the pit at Destro's ancestral home in Scotland and fails. Meanwhile, Dial Tone is discharged from the Joes and is hired to work on a communications project that turns out to be communicating with the creature. Flint is sent to spy on Dial Tone in disguise. Dial Tone gets the machine to work and Cobra Commander tells it to destroy Serpentor...