Cocalus' Daughters

Cocalus' daughters were the daughters of Cocalus. They killed Minos.

The Battle of the Labyrinth
They appeared in one of Percy's dreams, where Minos came to their father's castle in order to capture Daedalus. They tricked Minos into taking a bath where they used a weapon made by Daedalus (also their tutor) to kill Minos.