Percy Jackson and the Olympians: Legends

Cottus was one of the three Hecatonchires. He was the first to break a blood oath with a god and to be punished by the Furies, becoming a titan-sized living-prison called the Prison of the Damned. After the First Titan War, Cottus pledged a blood oath to Zeus, only to later betray him. Displeased by this betrayal, the Furies hunted him down to torture him without end, as they saw death would be too merciful for such a crime. He became an example to all, with his body being converted into a prison for those who followed his example.