Nightmare Moon is the original villain of the children's series, My Little Pony: Friendship is Magic. A stereotypical dark unicorn, Nightmare Moon is a minor player in the second Disney Vs Non Disney Villains War.
Disney Vs Non Disney Villains - Part Two
Nightmare Moon breaks free of her lunar prison and encounters Megavolt, a villain intent on killing her. Before Megavolt gets a chance to attack, Nightmare Moon lands a lunar module on his head. She makes her way to Earth, but Megavolt dogs her all the way. No sooner does he set up a camera-like laser than does Nightmare Moon blast him with electricity. Nightmare Moon's smile fades as Megavolt reveals the true power of his laser: rainbows. Nightmare Moon is eradicated before she can even flee.
Non Disney Villains Tournament
Dawn and Death
Nightmare Moon is part of a faction of dark beings including the Grand Duke of Owls, Samhain, and Dracula himself. She, however, meets a quick end when Lord Maliss attacks. Though Nightmare Moon tries to charge down Maliss, he stops her advance with a fireball. When she then tries to hit him with lightning, he deflects the blast. Maliss then uses his magic vision to encircle Nightmare Moon with a magical tornado, draining Moon from most of her powers. When Nightmare Moon gets up, Maliss transforms into a dragon and eats her.
Much later in the war, the Grand Duke of Owls resurrects Nightmare Moon as part of a gambit to betray the Legion of Darkness. When Devimon arrives to eliminate the Grand Duke, Nightmare Moon comes to her rescuer's aid. She blasts Devimon's hand with her magic, injuring the being. Before Devimon has a chance to respond, Nightmare Moon blasts a massive hole through his chest and destroys him. The two then formally declare their freedom.