Dark Nemus is a dark clone of Nemus and is his evil brother. He was the primary antagonist of the Backyard Gods Arc of UnMario: The Series. He is the leader of the Backyard Gods.
Dark Nemus makes his first appearance in The Backyard Gods Arc of UnMario: The Series in episode 65 as a shadow when Uniqua, The Goddess of Sleep tells him that they have kidnapped Mario and Luigi when they and some other guys have gone to relax on UnCarnival Backyard and he laughs eviley.
While Dark Nemus is not seen in the next episodes. His voice is still heard ordering the Backyard Gods to attack and telling them about their secret plan.
He appears again in episode 72 on a TV screen telling the Gods to combine their powers into one super attack. But it fails and he is also seen at the end of the episode, vowing revenge.
He is not seen in the next episodes until Episode 75 where he finds a legendary artifact called the Nightmare Claw which can paralyse an enemy. He puts it on Austin, the God of Laughter, to paralyse Mario and his friends to make them turn against eachother. But Austin destroys it and Dark Nemus's hand is seen leaving it in the stove to burn and his head is also shown with his eyes glowing red.
He is not seen again until episode 80 where he reveals himself and battles Mario and Luigi, he is defeated. But he tells them that they will never defeat him.
His last appearances are in episodes 85 and 86 where he kills the gods. He gets the gods's powers, turning into Giga Dark Nemus and finally fights Mario and Luigi, who turn Giga. But Mario and Luigi are turned back to normal size and are defeated when Nemus comes and revives them, telling them that the three of them must fuse, Mario and Luigi agree and the three fuse into Giga Saint Nemus. A big fight starts between the two gods and Giga Dark Nemus gains the upper hand until Giga Saint Nemus uses his ultimate attack, Heaven and @#!*% Buster!!! Giga Dark Nemus is killed and the day is saved.