The Fear Demons are the secondary antagonists of the Ducktales episode "Nothing to Fear". Created by Magica De Spell, they are each physical manifestations of the worst phobias of Scrooge McDuck, Huey, Dewey, and Louie, Doofus Drake, and Duckworth.
Fears by Appearance
The Limo Monster
Shortly after being washed, Scrooge's limousine transforms into an aggressive black panther to frighten Duckworth.
The villain of Huey, Dewey, and Louie's favorite video game, "Ducks of the Galaxy", leaps out of the television along with the hero, Flash Mallard and kills him with his laser gun, then proceeds to chase the boys. He appears in the final battle but he was disintegrated into pixels when one of the nephews tells him that "he's only a video game".
A peeled banana that Doofus Drake prepares to eat begs to be spared, with the added threat - as it grows into a giant monster - that it will eat him if he doesn't.
A monstrous vacuum cleaner appears in a storage closet, thwarting Duckworth's attempts of hiding from the Limo Monster in there.
Angry bill collectors appear at Scrooge's doorstep to harass him about paying his taxes. When Scrooge finds his Money Bin empty, they appear and threaten to take his nephews away. When Scrooge drives away from the bin, they run after him.
The school bully appears and demands Doofus' lunch money and threatens to strangle him if not. When Scrooge drives away from the bin, he chases them on his motor-bike throwing rocks.
A demonic manifestation of Huey, Dewey, and Louie's teacher appears at their windowsill to reprimand them for not doing their homework. When Scrooge drives away from the bin, she runs after them while throwing apples. She appears in the final battle but she poofs away after the nephews tell her "they've already done their homework" (she even apologizes before disappearing).
An abusive clone of Scrooge who cruelly belittles the boys and claims to have created the storm with his riches to scare the boys away so that he wouldn't have to put up with them anymore. He appears in the final battle but he was turned into a giant 1 cent coin before being poofed away into smoke after the nephews told him that "he's not Uncle Scrooge" and proceed to throw mud at the impostor.
Huey, Dewey, and Louie
Delinquent, heartless clones of the triplets cruelly belittle Scrooge and claim to have created the storm with their chemistry just to ruin his day. They appeared in the final battle but they shrink into nothingness after Scrooge told him that "his boys love him, therefore they're not his boys".
The Fear Cloud
The cause of the entire event, it ultimately turns against Magica, making her worst fear of her spells no longer working come true.