He-Man and the Masters of the Universe (1983)

S2E26 Three on a Dare

Man-At-Arms requires a sample of Rainbow Quartz to fix a frequency transmitter. The only source for this rare mineral is a cavern located within Snake Mountain! Adam and Cringer must brave Skeletor's territory to retrieve the Quartz. Meanwhile, Teela and three of her trainees, having accepted a dare, find themselves captured by Skeletor as well. With so many unexpected visitors in Snake Mountain, chaos is bound to erupt!