He-Man and the Masters of the Universe

Beast Man introduces Skeletor to the Shadowbeasts, large powerful creatures that attack at night in vast numbers. Knowing the creatures hate any light source, Skeletor and the Evil Warriors cause Mount Barathrum to explode sending out a large ominous could that blocks out the sun. Ram Man must face his fears after Teela is injured during the attack, as the heroes soon realize the Shadowbeasts are striking both the Royal Palace and Castle Grayskull!