The sirens are absolutely beautiful and seductive mythical creatures that endlessly sing and wail all day long to lure sailors that pass by their island. When they catch a sailor's attention with their singing, they sing in rhyme about their prey's desires (for example: Scrooge McDuck's love for money and gold). Once the sailor is within reach, they will summon their monster head to gorge their prey. However, if anyone were to steal their prey, they will become enraged and will unleash their fury upon them.
The Sirens are three heads of very beautiful female ducks with extremely long hair (one black, one brown, and one blonde). They have purple, limbless, and flabby bodies that are conjoined with an enormous, deformed, and hideous monster with sharp teeth and a long tongue.
Scrooge McDuck, his nephews, and King Homer were riding on their new yacht when Homer realizes that they are nearing the island of the sirens, warning that they must cover their ears and not hear them singing. Scrooge was unaware of their hypnotic powers at the moment when they attracted him with "Eyes of Gold". Scrooge, enchanted by their eyes and song, jumps off the yacht and swims to the Sirens as Homer and Scrooge's nephews chase after him. Just when Scrooge approaches them, the Sirens reveal a large monster hiding underneath them and attempted to eat Scrooge whole, until Homer catches Scrooge with a net and pulls him to safety with the Sirens chasing after them. Once on their yacht, the monster grabs Scrooge with its long tongue and tries to pull him back. Luckily, Dewey throws the anchor and nails its tongue right against a placed rock, hurting the monster and letting go of Scrooge from his tongue's grip. Angered that their prey has escaped and Dewey has harmed their monster, the Sirens sink down with their monster to recover.
The Sirens appear again later near the end of the episode, at night when they hear and see the Time Twister carrying Scrooge and his nephews whirl by their island. The sirens' monster surfaces up to see the noise, but doesn't notice the Twister. So then, the monsters and the sirens sink back underneath to sleep.