The Oarni were associated with the MaiaOssë and often aided his labours. They used their power to help Ossë drag the island where the Valar stood until they located to the Far Western land. They brought forth many pearls that contributed to the building of Ossë's house. They grew to love the songs made by the Solosimpi in their early days on Tol Eressëa.
The Oarni are often associated with the mermaids. However, though not necessarily in every case, the mermaids were thought to be fays or earthlings.