|First appearance||Filly Mermaids toy line|
Nautilus is a male Mermaid Filly, who oftens swims up to the surface to catch up on the news from land. He is also very informed on the events in Aquatica, which makes him very up-to-date on any kind of news compared to most other Fillys. Additionally, not only can he get moved easily to the point of felling tears, but the tears also becomes pearls in the ocean instantly.
He is in love with Carol.