Echo, an Oread.
In Greek mythology, the Oreads, or Orestiads, were the nymphs that inhabited mountains, valleys, and ravines, and were sometimes associated with the goddess Artemis. They were often classified from where they dwelled; for example, the Idaeae lived in Mt. Ida, while the Peliades were from Mt. Pelion.
The Heroes of Olympus
The Mark of Athena
While searching for supplies to repair the Argo II, Leo Valdez and Hazel Levesque meet Echo and several other Oreads who are all obsessed with Narcissus.