[PAR] [TLE] Achilles [SEP] In Greek mythology, Achilles ( , ; ] ) was a Greek hero of the Trojan War and the central character and greatest warrior of Homer's "Iliad".  His mother was the immortal nereid Thetis, and his father, the mortal Peleus, was the king of the Myrmidons. [PAR] [TLE] Pyrrhus (Royer) [SEP] Pyrrhus is an opera by the French composer Joseph-Nicolas-Pancrace Royer, first performed at the Académie Royale de Musique (the Paris Opera) on 26 October 1730.  It takes the form of a "tragédie en musique" in a prologue and five acts.  The libretto, by Fermelhuis, is based on the Greek myth of Pyrrhus, son of Achilles.
[PAR] [TLE] Achilles [ SEP ] In Greek mythology , Achilles ( , ; ] ) was a Greek hero of the Trojan War and the central character and greatest warrior of Homer 's " Iliad " . His mother was the immortal nereid Thetis , and his father , the mortal Peleus , was the king of the Myrmidons . [PAR] [TLE] Pyrrhus ( Royer ) [ SEP ] Pyrrhus is an opera by the French composer Joseph - Nicolas - Pancrace Royer , first performed at the Académie Royale de Musique ( the Paris Opera ) on 26 October 1730 . It takes the form of a " tragédie en musique " in a prologue and five acts . The libretto , by Fermelhuis , is based on the Greek myth of Pyrrhus , son of Achilles .
In Greek mythology, Pyrrhus is the grandson of what immortal nereid?
In Greek mythology , Pyrrhus is the grandson of what immortal nereid ?
Thetis
Thetis